Wireless Sensors For Nerve Integrity Monitoring Systems

ABSTRACT

A sensor including electrodes, a control module and a physical layer module. The electrodes are configured to (i) attach to a patient, and (ii) receive a first electromyographic signal from the patient. The control module is connected to the electrodes. The control module is configured to (i) detect the first electromyographic signal, and (ii) generate a first voltage signal. The physical layer module is configured to: receive a payload request from a console interface module or a nerve integrity monitoring device; and based on the payload request, (i) upconvert the first voltage signal to a first radio frequency signal, and (ii) wirelessly transmit the first radio frequency signal from the sensor to the console interface module or the nerve integrity monitoring device.

CROSS-REFERENCE TO RELATED APPLICATIONS

The application is a divisional of U.S. patent application Ser. No.14/455,285 filed on Aug. 8, 2014. The entire disclosure of the aboveapplication is incorporated herein by reference.

FIELD

The present disclosure relates to nerve integrity monitoring systems anddevices.

BACKGROUND

The background description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent the work is described in thisbackground section, as well as aspects of the description that may nototherwise qualify as prior art at the time of filing, are neitherexpressly nor impliedly admitted as prior art against the presentdisclosure.

A nerve integrity monitoring (NIM) system can include a stimulationprobe device, sensors, an electrode connection box, and anelectromyography (EMG) monitoring device. The stimulation probe deviceis used to stimulate nerve and/or muscle activity. As an example, astimulation probe device may include a stimulating electrode tip. Asurgeon may touch a location on a patient with the electrode tip toprovide a voltage and/or current to a location on the patient andstimulate nerve activity and as a result a muscle response (or muscleactivity). A reference patch may be attached to the patient away from(i) the sensors, and (ii) an area being stimulated. An electrode of thereference patch can be at a reference potential. The sensors can includeelectrodes that are attached to the patient and used to monitor themuscle activity. A voltage potential between the electrode tip of thestimulation probe device and the reference patch and voltage potentialsindicated by outputs of the sensors may be provided via wires to theelectrode connection box. The wires are plugged into respective jacks inthe electrode connection box.

The electrode connection box can have channels respectively for: avoltage potential of the stimulation probe device; a voltage potentialof the reference patch; and output voltages of the sensors. Theelectrode connection box may filter signals received from thestimulation probe device and sensors and provide corresponding signalsto the EMG monitoring device. Depending on the surgical procedure beingperformed, a large number of cables may be used to transmit informationbetween (i) the stimulation probe device and sensors and (ii) theelectrode connection box. As an example, 1-32 channels may be usedduring a surgical procedure. Each of the channels may correspond to arespective twisted pair cable (each cable having a twisted pair ofwires). Each of the cables connected to the sensors is secured to apatient via the electrodes of the sensors, extends away from thepatient, and is routed outside of a sterile field (or environment) inwhich the patient is located to the EMG monitoring device.

In one example, a certain type of sensor may be used during thyroidsurgery to monitor nerves in intrinsic laryngeal musculature of apatient. Injury to a recurrent laryngeal nerve (RLN) is one of the mostserious complications of thyroid surgery. An endotracheal tube can beused during thyroid surgery to open an airway and provide air to lungsof the patient. The endotracheal tube can include electrodes that aredesigned to contact vocal chords of the patient to facilitate EMGmonitoring of the vocal chords during surgery.

As an example, a stimulating electrode may be placed on a vagus nerve inthe neck of the patient to deliver continuous low-level stimulation tonerve endings. A baseline of nerve function is obtained and subsequentEMG responses are monitored via the electrodes connected to theendotracheal tube. Electromyographic signals are generated and detectedby the electrodes and provided to an EMG monitoring device. The EMGmonitoring device monitors changes in the electromyographic signals todetect changes in intrinsic laryngeal musculature of the patient.Between stimulations, nerves can be at risk due to surgical incision,and/or “blind” trauma caused by stretching, heating, compressing, and/ormanipulating tissues of a patient during tumor/thyroid removal. The EMGresponses are charted in real time to provide feedback with regard tothe conditions of the nerves.

SUMMARY

A sensor is provided and includes electrodes, a control module and aphysical layer module. The electrodes are configured to (i) attach to apatient, and (ii) receive a first electromyographic signal from thepatient. The control module is connected to the electrodes. The controlmodule is configured to (i) detect the first electromyographic signal,and (ii) generate a first voltage signal. The physical layer module isconfigured to: receive a payload request from a console interface moduleor a nerve integrity monitoring device; and based on the payloadrequest, (i) upconvert the first voltage signal to a first radiofrequency signal, and (ii) wirelessly transmit the first radio frequencysignal from the sensor to the console interface module or the nerveintegrity monitoring device.

In other features, a method is provided and includes: receiving, at asensing module, a first electromyographic signal from a patient viaelectrodes, wherein the sensing module is directly connected to theelectrodes; generate a first voltage signal based on theelectromyographic signal; generate a first voltage signal based on theelectromyographic signal; upconverting the first voltage signal to afirst radio frequency signal; and based on the payload request,wirelessly transmitting the first radio frequency signal from thesensing module to the console interface module or the nerve integritymonitoring device.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description, the claims and the drawings. Thedetailed description and specific examples are intended for purposes ofillustration only and are not intended to limit the scope of thedisclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a wireless nerve integrity monitoring(WNIM) system in accordance with the present disclosure.

FIG. 2 is a functional block diagram of a sensing module, a consoleinterface module and a NIM device in accordance with the presentdisclosure.

FIG. 3 is a functional block diagram of another sensing module andanother NIM device in accordance with the present disclosure.

FIG. 4 is a functional block diagram of another sensing module inaccordance with the present disclosure.

FIG. 5 is a functional block diagram of a stimulation probe device inaccordance with the present disclosure.

FIG. 6 is a functional block diagram of a portion of the stimulationprobe device in accordance with the present disclosure.

FIG. 7A is a perspective view of a three-pad sensor with an electroniccontrol module assembly in accordance with the present disclosure.

FIG. 7B is a bottom perspective view of a portion of the three-padsensor of FIG. 7A without the electronic control module assembly andillustrating corresponding contact pads.

FIG. 8 is a perspective view of an EMG endotracheal tube assembly inaccordance with the present disclosure.

FIG. 9 is another perspective view of the EMG endotracheal tube assemblyof FIG. 8.

FIG. 10 is another perspective view of the EMG endotracheal tubeassembly of FIG. 8.

FIG. 11 is a side view of a housing of the EMG endotracheal tubeassembly of FIG. 8.

FIG. 12 is a bottom view of the housing of the EMG endotracheal tubeassembly of FIG. 8.

FIG. 13 is an exploded view of the housing and corresponding electronicassembly of the EMG endotracheal tube assembly of FIG. 8.

FIG. 14 is a plot of a stimulation pulse and a corresponding evokedresponse signal.

FIG. 15 is a timing diagram illustrating a periodic synchronization(SYNC) interval with two time slots per sensor in accordance with thepresent disclosure.

FIG. 16 is a timing diagram illustrating a periodic SYNC interval with asingle time slot per sensor in accordance with the present disclosure.

FIG. 17 is a timing diagram illustrating a periodic SYNC interval with asingle slot per sensor and an increased number of sensor slots per framein accordance with the present disclosure.

FIG. 18 is a signal flow diagram illustrating a sensor joining andcommunicating in a WNIM system in accordance with the presentdisclosure.

FIG. 19 is a signal flow diagram illustrating a stimulation devicejoining and communicating in a WNIM system in accordance with thepresent disclosure.

FIG. 20 illustrates a method of operating a sensor and a consoleinterface module and/or NIM device in accordance with the presentdisclosure.

FIG. 21 illustrates a method of powering-up a sensor in accordance withthe present disclosure.

FIG. 22 illustrates a WNIM method of operating a stimulation probedevice, one or more sensors, and a console interface module and/or NIMdevice in accordance with the present disclosure.

FIG. 23 is a side perspective view of a portion of another EMGendotracheal tube assembly in accordance with the present disclosure.

FIG. 24 an exploded view of a housing and corresponding electronicassembly of the EMG endotracheal tube assembly of FIG. 23.

FIG. 25 is a perspective view of a sensor assembly incorporating amodular control module assembly in accordance with the presentdisclosure.

FIG. 26 is a side view of the modular control module assembly of FIG. 25connected to a patch.

FIG. 27 is a bottom perspective view of the modular control moduleassembly of FIG. 25 illustrating pads of the patch.

FIG. 28 is a perspective view of the modular control module assembly ofFIG. 25 and the patch.

FIG. 29 is a bottom perspective view of the modular control moduleassembly of FIG. 25 and the patch.

FIG. 30 is a perspective view of the modular control module assembly ofFIG. 25 connected to a pin electrode adaptor in accordance with thepresent disclosure.

FIG. 31 is a side view of the modular control module assembly of FIG. 25connected to the pin electrode adaptor.

FIG. 32 is a bottom perspective view of the modular control moduleassembly of FIG. 25 connected to the pin electrode adaptor.

FIG. 33 is a top perspective view of the modular control module assemblyof FIG. 25 and the pin electrode adaptor.

FIG. 34 is a bottom perspective view of the modular control moduleassembly of FIG. 25 and the pin electrode adaptor.

FIG. 35 is a circuit diagram of a portion of a power module inaccordance with the present disclosure.

In the drawings, reference numbers may be reused to identify similarand/or identical elements.

DESCRIPTION

Any clutter and/or time inefficiencies in an operating room that can beeliminated and/or minimized is advantageous to both hospital personaland a patient. Nerve integrity monitoring (NIM) systems currently haveextensive cabling. Most of the cabling corresponds to transporting ordelivery evoked response signals from sensors to a NIM device, as aresult of stimulated nerve activity in muscles of a patient. Varioustechniques are disclosed below, which reduce and/or eliminate cablesused in a NIM system, reduce and/or minimize certain time inefficienciesassociated with current NIM systems, and minimize power consumption.

FIG. 1 shows a wireless nerve integrity monitoring (WNIM) system 10. TheWNIM system 10, as shown, includes sensors 12, 13, a stimulation probedevice 14, a wireless interface adaptor (WIA) 16 and a NIM device 18.The WIA 16 includes a console interface module (CIM), which is shown inFIG. 2, and an interface 20 (e.g., a 32-pin connector) for connecting tothe NIM device 18. The WIA 16 is shown as being plugged into a back sideof the NIM device 18. Although the WIA 16 is shown as being plugged intothe NIM device 18 via the interface 20, the WIA 16 may be separate fromthe NIM device 18 and wirelessly communicate with the NIM device 18. Thesensors 12, 13 and the stimulation probe device 14 wirelesslycommunicate with the CIM and/or the NIM device 18. In one embodiment,the WIA 16 is connected to the NIM device 18 and wirelessly communicateswith the sensors 12, 13 and the stimulation probe device 14. Informationdescribed below as being transmitted from the NIM device 18 to the CIMmay then be relayed from the CIM to the sensors 12, 13 and/or thestimulation probe device 14. Information and/or data described below asbeing transmitted from the sensors 12, 13 and/or the stimulation probedevice 14 to the CIM may then be relayed from the CIM to the NIM device18.

The WIA 16: transfers signals between (i) the NIM device 18 and (ii) thesensors 12, 13 and the stimulation probe device 14; and/or addsadditional information to the signals received from the NIM device 18prior to forwarding the signals to the sensors 12, 13 and/or stimulationprobe device 14, as described below. The WIA 16 may: operate essentiallyas a pass through device; be a smart device and add and/or replaceinformation provided in received signals; and/or generate signalsincluding determined information based on received signals. For example,the WIA 16 may receive a payload request signal from the NIM device 18and determine a delay time between when the payload request was receivedand when a next synchronization (SYNC) request signal is to betransmitted. This is described in further detail with respect to FIGS.18 and 22. The WIA 16 allows the NIM device 18 to be compatible withlegacy hardware. The WIA 16 may be unplugged from the NIM device 18 anda traditional electrode connection box may be connected to the WIA 16using the same interface of the NIM device 18 as the WIA 16. The WIA 16replaces cables traditionally connected between (i) a NIM device 18 and(ii) sensors 12, 13 and a stimulation probe device 14. This eliminateswires traversing (extending from within to outside) a sterile field inwhich a patient is located.

As another example, the WIA 16 may receive signals from the sensors 12,13 and/or the stimulation probe device 14. The signals from the sensors12, 13 and/or the stimulation probe device 14 may indicate voltages,current levels, durations, amplitudes, etc. and/or the WIA device 16 maydetermine, for example, durations and amplitudes based on the receivedsignals. The received signals and/or the determined information may beforwarded to the NIM device 18 for evaluation and/or for display on thescreen of the NIM device 18.

Although two types of sensors 12, 13 are shown in FIG. 1, other types ofsensors may be incorporated in the WNIM system 10. Another type ofsensor is shown and described with respect to FIGS. 8-13. The sensors 12of the first type are referred to as pin sensors and include respectivepairs of pins 21 (or needles) that are inserted into, for example,muscle tissue of a patient. The sensors 13 of the second type arereferred to as surface sensors and are adhered to skin of a patientover, for example, muscle tissue. The pin sensors 12 may, for example,be used to detect voltage potentials between the respective pairs ofpins 21 of the pin sensors 12. The surface sensors 13 may, for example,be used to detect voltage potentials between respective pads of thesurface sensors 13. The pin sensors 12 may each include two pins asshown or may include a different number of pins. The pins may bereferred to as electrodes. Each of the surface sensors 13 may includetwo or more pads. The pads may be referred to as electrodes.

One or more of the sensors 12, 13 may include a third electrode (pin orpad), as is further described with respect to FIGS. 7A-7B. The sensors12, 13 are used to digitize nerve and/or muscle activity and wirelesslytransmit this information to the CIM and/or the NIM device 18. Thesensors 12, 13 may alert the CIM and/or the NIM device 18 of bursts(e.g., increases in voltages of evoked response signals) in nerve and/ormuscle activity. An evoked response signal refers to a signal generatedin a tissue of a patient as a result of a stimulation signal generatedby the stimulation probe device 14.

The stimulation probe device 14 is used to stimulate nerves and/ormuscle in the patient. The stimulation probe device 14 includes: ahousing 30 with a grip 32; one or more electrodes 34 (shown having twoelectrodes); a switch 36; a control module (an example of which is shownin FIG. 5); and an input 38 for connection to a reference pad (or patch)40, via a cable 42. Although the stimulation probe device 14 is shownhaving a bifurcated tip with two electrodes 34, the stimulation probedevice 14 may have one or more electrodes 34. The electrodes 34 areseparated and insulated from each other and may extend within a tube 44to the housing 30. The switch 36 may be used to turn ON the stimulationprobe device 14 and/or to apply a stimulation pulse to the electrodes34. An example of a stimulation pulse is shown in FIG. 14. Thestimulation pulse may be manually generated by actuating the switch 36or may be generated via the NIM device 18 and/or the WIA 16 via the CIM.The NIM device 18 and/or the CIM may signal the control module of thestimulation probe device 14 to generate one or more stimulation pulsesto stimulate one or more nerves and/or muscles in proximity of theelectrodes 34. The reference patch 40 is used to provide a referencevoltage potential. One or more voltage potentials between one or more ofthe electrodes 34 and the reference patch 40 may be determined by: thecontrol module of stimulation probe device 14; a control module of theNIM device 18 (examples of which are shown in FIGS. 2-3); and/or acontrol module of the CIM (examples of which are shown in FIGS. 2-3).

The stimulation probe device 14 may wirelessly transmit information tothe CIM and/or NIM device 18. The information may include: timinginformation; voltage potentials between the electrodes 34; voltagepotentials between the reference patch 40 and one or more of theelectrodes 34; number of stimulation pulses; pulse identifiers (IDs);voltages and current levels of stimulation pulses generated; andamplitudes, peak magnitudes and/or durations of stimulation pulsesgenerated. The timing information may include: start and end times ofstimulation pulses; durations of stimulation pulses; and/or time betweenstimulation pulses.

In another embodiment, the WIA 16 is not included in the WNIM system 10.In this embodiment, the NIM device 18 wirelessly communicates directlywith the sensors 12, 13 and the stimulation probe device 14. This mayinclude communication with the sensors 12, 13 and the stimulation probedevice 14 shown in FIG. 1 and/or communication with other sensors (e.g.,the sensor shown in FIGS. 8-13) and/or stimulation devices. The WNIMsystem 10 may include any number of sensors and/or stimulation probedevices.

Referring now to FIG. 1 and FIG. 2, which shows a sensing module 50, aCIM 52 and a NIM device 54. The sensing module 50 wirelesslycommunicates with the CIM 52 and/or with the NIM device 54 via the CIM52. The sensing module 50 may be included in any of the sensorsdisclosed herein including the sensors shown in FIGS. 1, 7A-7B and 8-13.The CIM 52 may be included in the WIA 16 of FIG. 1.

The sensing module 50 includes a control module 56 (e.g., amicroprocessor), a memory 58, and a physical layer (PHY) module 60(e.g., a transceiver and/or radio). The control module 56 detectselectromyographic signals generated in tissue of a patient viaelectrodes 62 (e.g., pins or pads). The electromyographic signals may bein the form of voltage signals having voltage potentials. The controlmodule 56 includes a gain module 63 (e.g., an amplifier), a filteringmodule 64 (e.g., one or more filters) and a baseband module 66. Thebaseband module 66 may include an upconverter and a downconverter. Thegain module 63 amplifies the electromyographic signals to generateamplified signals. The filtering module 64 may operate as a bandpassfilter and filter out (i) frequencies of the amplified signals outsideof predetermined frequency range, and (ii) a direct current (DC)voltage. This can eliminate and/or minimize noise, such as 60 Hz noise.The filtering module 64 generates a baseband signal.

The baseband module 66 may include an analog-to-digital (A/D) convertingmodule 70 (e.g., an A/D converter) and convert the baseband signal (ananalog signal) from the filtering module 64 to a digital baseband (BB)signal. The BB module 66 and/or the A/D converting module 70 may samplethe output of the filtering module 64 at a predetermined rate togenerate frames, which are included in the digital BB signal. By A/Dconverting signals at the sensor as opposed to performing an A/Dconversion at the CIM 52 or the NIM device 54, opportunities for signalinterference is reduced.

The BB module 66 may then upconvert the digital BB signal to anintermediate frequency (IF) signal. The BB module 66 may performdirect-sequence spread spectrum (DSSS) modulation during upconversionfrom the digital BB signal to the IF signal. The BB module 66 mayinclude a mixer and oscillator for upconversion purposes. The BB module66 and/or the control module 56 may compress and/or encrypt BB signalstransmitted to the PHY module 60 prior to upconverting to IF signalsand/or may decompress and/or decrypt signals received from the PHYmodule 60.

The BB module 66 may provide a received signal strength indication(RSSI) indicating a measured amount of power present in a RF signalreceived from the CIM 52. This may be used when determining which ofmultiple CIMs the sensor is to communicate with. The control module 56may select a CIM corresponding to a SYNC request signal and/or a payloadrequest signal having the most power and/or signal strength. This mayinclude (i) selecting a channel on which the SYNC request signal and/orthe payload request signal was transmitted, and (ii) communicating withthe CIM on that channel. This allows the control module 56 to select theclosest and proper CIM. This selection may be performed when the sensorhas not previously communicated with a CIM, is switching to a differentWNIM network, and/or has been reset such that the sensor does not have arecord of communicating with a CIM. In one embodiment, the sensors areunable to be reset.

The memory 58 is accessed by the control module 56 and stores, forexample, parameters 72. The parameters 72 may include parametersprovided in SYNC request signals and/or parameters associated withelectromyographic signals generated via the electrodes. The parametersassociated with electromyographic signals may include voltages, currentlevels, amplitudes, peak magnitudes, pulse durations, etc.

The PHY module 60 includes a transmit path 74 (or transmitter) and areceiver path 76 (or receiver). The transmit path 74 includes amodulation module 78 (e.g., a modulator) and an amplification module 80(e.g., an amplifier). The modulation module 78 modulates and upconvertsthe IF signal to generate a radio frequency (RF) signal. This mayinclude Gaussian frequency-shift keying (GFSK) modulation. Themodulation module 78 may include, for example, a filter, a mixer, and anoscillator (collectively identified as 82). The amplification module 80may include a power amplifier 84, which amplifies the RF signal andtransmits the RF signal via the antenna 86.

The receiver path 76 includes a second amplification module 90 and ademodulation module 92 (e.g., a demodulator). The amplification module90 may include a low-noise amplifier (LNA) 94. The second amplificationmodule 90 amplifies RF signals received from the CIM 52. Thedemodulation module 92 demodulates the amplified RF signals to generateIF signals. The IF signals are provided to the BB module 66, which thendownconverts the IF signals to BB signals. The demodulation module 92may include, for example, a filter, a mixer, and an oscillator(collectively identified as 96). The A/D converting module 70 mayinclude a digital-to-analog (D/A) converter to convert the BB signals toanalog signals. The RF signals received from the CIM 52 may include, forexample, SYNC request signals or portions thereof, as further describedbelow. Examples of information included in the SYNC request signals isshown and described below with respect to Tables 1-4.

The CIM 52 includes a PHY module 100, a control module 102, a memory104, and a NIM interface 106 (e.g., 32 pin connector). The PHY module100 includes a receive path (or receiver) 108 and a transmit path (ortransmitter) 110. The receive path 108 includes an amplification module112 and a demodulation module 114. The amplification module 112amplifies RF signals received from the sensing module 50 and/or fromother sensor modules and/or stimulation probe devices. The amplificationmodule 112 may include a LNA 115. The demodulation module 114demodulates and downconverts the amplified RF signals to generate IFsignals. The demodulation module 114 may include a filter, mixer, and anoscillator (collectively referred to as 117). The transmit path 110includes a modulation module 116 and an amplification module 118. Themodulation module 116 modulates and upconverts IF signals from thecontrol module 102 to generate RF signals. This may include Gaussianfrequency-shift keying (GFSK) modulation. The modulation module 116 mayinclude, for example, a filter, a mixer, and an oscillator (collectivelyidentified as 119). The amplification module 118 transmits the RFsignals to the sensing module 50 via an antenna 120 and/or to othersensor modules and/or stimulation probe devices. The amplificationmodule 118 may include a power amplifier 121.

The control module 102 includes a BB module 124 and a filtering module126. The BB module 124 converts IF signals received from the PHY module100 to BB signals and forwards the BB signals to the filtering module126. The BB module 124 also converts BB signals from the filteringmodule 126 to IF signals, which are forwarded to the modulation module116. The BB module 124 may include a D/A converting module 128. The D/Aconverting module 128 may include an A/D converter to convert analogsignals from the filtering module 126 to digital signals. The D/Aconverting module 128 may include a D/A converter to convert digitalsignals from the PHY module 100 to analog signals. In one embodiment,the BB module 124 does not include the D/A converting module 128 anddigital signals are passed between the filtering module 126 and the PHYmodule 100. The BB module 124 may attenuate signals received from thedemodulation module 114 to have amplitudes similar to amplitudes ofsignals received at the gain module 63 and/or the filtering module 64 ofthe sensing module 50. The filtering module 126 may be a bandpass filterand remove frequencies of signals outside a predetermined range and/orDC signals. This can eliminate and/or minimize noise, such as 60 Hznoise. The BB module 124 and/or the control module 102 may compressand/or encrypt signals transmitted to the modulation module 116 and/ordecompress and/or decrypt signals received from the demodulation module114. Although the CIM 52 is shown as being connected to the NIM device54 via the NIM interface 106, the CIM 52 may be separate from the NIMdevice 54 and wirelessly communicate with the NIM device 54 via the PHYmodule 100.

The memory 104 is accessed by the control module 102 and stores, forexample, parameters 130. The parameters 130 may include parametersprovided in SYNC request signals and/or parameters associated withelectromyographic signals received via the electrodes 62. The parameters130 associated with electromyographic signals may include voltages,current levels, amplitudes, peak magnitudes, pulse durations, etc. andmay include or be the same as the parameters 72. The memory may alsostore synchronization requests 132, which are defined below.

The NIM device 54 may include a control module 140, a PHY module 142, aCIM interface 144, a display 146 and a memory 148. The control module140: generates payload request signals; receives data payload signalsfrom the sensing module 50 and/or other sensing modules and stimulationprobe devices via the CIM 52; and displays electromyographic signalsand/or other related information on the display 146. The PHY module 142may transmit signals to and receive signals from the control module 140via the interfaces 106, 144 as shown or wirelessly via an antenna (notshown). The memory 148 is accessed by the control module 140 and storesthe parameters 130 and may store payload requests 150, which are definedbelow.

The control modules 56, 126, the BB modules 66, 128, the PHY modules 60,100, and/or one or more modules thereof control timing of signalstransmitted between the sensing module 50 and the CIM 52. This isdescribed in further detail below with respect to FIGS. 15-19 and 22.The PHY modules 60, 100 may communicate with each other in apredetermined frequency range. As an example, the PHY modules 60, 100may communicate with each other in 2.0-3.0 giga-hertz (GHz) range. Inone embodiment, the PHY modules 60, 100 transmit signals in a 2.4-2.5GHz range. The PHY modules 60, 100 may communicate with each other viaone or more channels. The PHY modules 60, 100 may transmit data atpredetermined rates (e.g., 2 mega-bits per second (Mbps)). The CIM 52and/or the NIM device 54 may set the frequency range, the number ofchannels, and the data rates based on: the number of sensor modules inand actively communicating in the WNIM system 10; the number ofstimulation probe devices in and actively communicating in the WNIMsystem 10; the types of the sensors; the number of channels per sensor;the speed per channel of each of the sensors; the number of channels perstimulation probe device, and/or the speed per channel of thestimulation probe devices.

Referring now to FIG. 1 and FIG. 3, which shows the sensing module 50and a NIM device 162. The sensing module 50 includes the control module56, the memory 58 and the PHY module 60. The control module 56 includesthe gain module 63, the filtering module 64 and the BB module 66. Thecontrol module 56 detects electromyographic signals via the electrodes62. The control module 56 reports data associated with theelectromyographic signals to the NIM device 162 via the PHY module 60.The control module 56 also receives signals (e.g., synchronizationrequest signals) from the NIM device 162 via the PHY module 60.

The NIM device 162 includes a control module 164, a memory 166, a PHYmodule 168, and the display 146. Functionality of the CIM 52 of FIG. 2is included in the NIM device 162. The PHY module 168 includes a receivepath 170 (or receiver) and a transmit path 172 (or transmitter). Thereceive path 170 includes an amplification module 174 and a demodulationmodule 176. The amplification module 174 via a LNA 175 amplifies RFsignals received from the sensing module 50 and/or from other sensormodules and/or stimulation probe devices. The demodulation module 176demodulates and downconverts the amplified RF signals to generate IFsignals. The transmit path 172 includes a modulation module 178 and anamplification module 180. The modulation module 178 and theamplification module 180 may operate similar to the modulation module116 and the amplification module 118. The amplification module 118 mayinclude a power amplifier 182 and transmits RF signals via an antenna183 to the sensing module 50 and/or to other sensor modules and/orstimulation probe devices.

The control module 164 includes a BB module 184 and a filtering module186. The BB module 184 converts IF signals received from the PHY module168 to BB signals and forwards the BB signals to the filtering module186. The BB module 184 also converts BB signals from the filteringmodule 186 to IF signals, which are forwarded to the modulation module178. The BB module 184 may include a D/A converting module 188. The D/Aconverting module 188 may include an A/D converter to convert analogsignals from the filtering module 186 to digital signals. The D/Aconverting module 188 may include a D/A converter to convert digitalsignals from the PHY module 168 to analog signals. In one embodiment,the BB module 184 does not include the D/A converting module 188 anddigital signals are passed between the filtering module 186 and the PHYmodule 168. The BB module 184 may attenuate signals received from thedemodulation module 176 to have amplitudes similar to amplitudes ofsignals received at the gain module 63 and/or the filtering module 64 ofthe sensing module 50. The filtering module 186 may be a bandpass filterand remove frequencies of signals outside a predetermined range and/orDC signals. This can eliminate and/or minimize noise, such as 60 Hznoise. The BB module 184 and/or the control module 164 may compressand/or encrypt signals transmitted to the modulation module 178 and/ordecompress and/or decrypt signals received from the demodulation module176.

Referring now to FIGS. 2-3, the BB module 66 of the sensing module 50may provide a received signal strength indication (RSSI) indicating ameasured amount of power present in a RF signal received from the NIMdevice 162. This may be used when determining which of multiple NIMdevices to communicate with. The control module 56 may select a NIMdevice corresponding to a SYNC request signal and/or a payload requestsignal that has the most power and/or signal strength. This may includeselecting a channel on which the SYNC request signal and/or the payloadrequest signal was transmitted and communicating with the CIM 52 and/orthe NIM device 162 on that channel. This allows the control module 56 toselect the closest and proper NIM device. This selection may beperformed when the corresponding sensor has not previously communicatedwith the NIM device 162 and/or other NIM devices and/or has been resetsuch that the sensor does not have a record of communicating with theNIM device 162 and/or other NIM devices.

The memory 166 may store the parameters 130, the payload requests 150and/or the SYNC requests 132. The memory 166 may store the SYNC requestsand may not store the payload requests. This is because the NIM device162 may generate SYNC requests and not payload requests.

Referring now to FIG. 1 and FIG. 4, which shows a sensing module 200.The sensing module 200 may be included in any of the sensors disclosedherein. For example, the sensing module may be used on any of thesensors shown in FIGS. 1-4, 7A-13, and 23-34. The sensing module 200includes the control module 202, a PHY module 204, a power module 206, apower source 208, a temperature sensing module 210, an A/D converter212, and an accelerometer 214. Although shown separate from the controlmodule 202, the PHY module 204, the power module 206, the temperaturesensing module 210 and/or the A/D converter 212 may be included in andas part of the control module 202.

The control module 202 includes the gain module 63, the filtering module64 and the BB module 66 of FIG. 2. The PHY module 204 includes themodulation module 78, the demodulation module 92 and the amplificationmodules 80, 90 of FIG. 2.

The control module 202, the PHY module 204, the temperature sensingmodule 210, and the A/D converter 212 operate based on power from thepower module 206. The power module 206 receives power from the powersource (e.g., a battery). The power module 206 may include a switch 216as shown (or a pull-tab) to turn ON and/or OFF the power module 206 andthus turn ON and/or OFF the sensing module 200 and/or the correspondingsensor. The switch 216 may be manually operated or may be operated bythe power module 206, the control module 202 and/or the PHY module 204.In one embodiment, the switch 216 is manually operated and at leastpartially exposed on an exterior of the sensing module 200 and/orcorresponding sensor housing. In another embodiment, the switch 216includes one or more transistors located in the control module 202, thePHY module 204, and/or in the power module 206, as shown. If included inone of the modules 202, 204, 206, the switch 216 is not exposed on anexterior of the sensing module 200 and/or the corresponding sensorhousing. The state of the switch 216 may be controlled by the controlmodule 202, the PHY module 204, and/or the power module 206 based onsignals received from the electrodes 62, the CIM 52, and/or the NIMdevice 162 of FIGS. 2-3. Transitioning the switch 216 via one of themodules 202, 204, 206 from a first state to a second state to turn ON atleast a portion of the sensor and/or at least a portion of the one ormore of the modules 202, 204, 206 may be referred to as an “auto-start”.

The sensing module 200 may operate in: a high power mode (fully poweredmode), a low (or idle) power mode (partially powered or transmittingless frequently then when in the high power mode), a sleep mode, or OFF.Operation in and transition between these modes may be controlled by oneor more of the modules 202, 204, 206. As an example, the sensor may beOFF (or dormant) while being shipped and/or not in use. The sensor mayalso be OFF if: not yet communicated with a CIM and/or NIM device; aconnection has not yet been established between the sensing module 200and a CIM and/or NIM device; the sensor has not yet been assigned to aCIM and/or NIM device; and/or the sensor has not yet been assigned oneor more time slots in which to communicate with a CIM and/or NIM device.

Transitioning to the low power mode, the sleep mode and/or to OFFdecreases power consumption and can aid in minimizing size of the powersource 208. While partially powered, the control module 202 and/orportions of the control module 202 and the PHY module 204 may bedeactivated. The receiver path of the PHY module 204 may remainactivated to (i) receive signals from the CIM 52 and/or portions of thecontrol module 202, and (ii) detect electromyographic signals. Thetransmit path 74 of the PHY module 204 and/or other portions of thesensor that are not experiencing activity may be deactivated.Transitioning between the stated modes is further described below.

When a surgery is performed, an operating room is generally kept at alow temperature. This in turn can decrease temperature of a patient.Studies have shown that if a patient is kept warm (e.g., within apredetermined range of a predetermined temperature or a normal bodytemperature, such as 98.6° F.) better outcomes are achieved. To maintaina temperature of a patient, heaters may be used to blow warm air underthe patient and/or heat portions of a table on which a patient is lying.The patient may also be covered or wrapped in blankets. If a heater isbroken, accidentally disconnected, not setup properly and/or isoperating improperly, the temperature of the patient can drop.Unfortunately, there can be a long lag time from when the heaters failto when a decrease in the temperature of the patient is detected. By thetime the decrease in the temperature of the patient is detected by, forexample, a surgeon or surgical assistant, the temperature of the patientmay have been below the predetermined range for an extended period oftime.

To aid in early detection of changes in temperatures of a patient, thesensor includes the temperature sensing module, which may be used todetect a temperature where the sensor is located. This temperature maybe based on or represent a temperature of a portion of a patient onwhich the sensor is attached. While the temperature sensor may not be indirect contact and/or directly indicate a temperature of the portion ofthe patient, the temperature sensor can provide a temperature signalindicative of an average temperature in a proximate area of thetemperature sensor.

Referring again also to FIG. 1, one or more of the sensors 12, 13 mayinclude a temperature sensing module (e.g., the temperature sensingmodule 210) and/or an accelerometer (e.g., the accelerometer 214). Byincluding temperature sensing modules in sensors, temperatures ofvarious points on a patient may be monitored. This further aids in earlydetection of changes in temperatures of a patient. The sensors providean earlier indication of a temperature issue than a sensor used todetect a change in a core body temperature of the patient, as the limbsor exterior of the body tends to decrease in temperature quicker thanthe core body temperature. The core body temperature may refer to, forexample, an internal temperature within a trunk (or chest) of the body.

The temperature sensing module 210 includes a first transistor 220 and asecond transistor 222. The first transistor 220 may be transitionedbetween states to supply current to the second transistor 222. Thisturns ON the temperature sensing module 210. The second transistor 222is configured to detect a temperature. As an example, the firsttransistor 220 may be a metal-oxide-semiconductor field-effecttransistor (MOSFET) and includes a drain, a gate and a source. Thesecond transistor 222 may be a bipolar junction transistor (BJT) andincludes a collector, a base and an emitter. The transistors 220, 222are shown for example purposes only, one or more of the transistors 220,222 may be replaced with other transistors or other similarly operatingcircuitry. The drain is connected to and receives current from the powermodule 206. The gate is connected to and receives a control signal fromthe control module 202. The source of the first transistor 220 isconnected to the collector and the base. The collector is connected to aground terminal 224. The collector and the emitter are also connected tothe A/D converter 212.

The second transistor 222 is connected in a diode configuration.Temperature dependence of the base-to-emitter voltage (Vbe) is the basisfor temperature measurement. The base-to-emitter voltage Vbe isdependent on temperature while (i) the power source 208 and the powermodule 206 supply a constant level of current to the collector via thefirst transistor 220, and (ii) a voltage across the base and thecollector is zero. The voltage across the base (or collector) and theemitter is detected by the A/D converter. The detected voltage isconverted to a temperature via the control module 202. The controlmodule 202 receives a digital signal from the A/D converter anddetermines the temperature. The temperature may be determined using, forexample, expression 1, where A is a predetermined multiplier constantand B is a predetermined offset constant.

A·Vbe+B  [1]

In addition to detecting electromyographic signals and temperature, thesensing module 200 may also detect other parameters, such as heart rate,respiration rate, and/or muscle spasms. These parameters may bedetermined via one or more of the control modules 202, 102, 140, 164 ofthe sensor, the CIM 52 and the NIM devices 54, 162 of FIGS. 2-3. The NIMdevices 54, 162 may generate an alert signal and/or display theseparameters on the display 146. This information may also be used toprovide an early indication that a patient is coming out from anesthesiaprematurely. The electrodes 62 may be monitored for EMG purposes as wellas for heart rate, respiration rate, and/or muscle spasms purposes. Todetect this information, the sensor may be attached to (or mounted on) atrunk of a patient.

A heart rate may be in a same frequency band as an electromyographicsignal. A heart rate is periodic unlike an electromyographic signal. Avoltage potential detected as a result of a beating heart may have alarger amplitude (or magnitude) than amplitudes (or magnitudes) of anelectromyographic signal. A respiration rate is typically in a lowerfrequency band than an electromyographic signal. A muscle spasm may havea distinguishable frequency and/or distinguishable frequency band. Thus,one or more of the control modules 202, 102, 140, 164 may distinguishbetween signals or portions of signals corresponding to a heart rate, arespiration rate, and an electromyographic signal based on thesedifferences. If the control module 202 of the sensor detects heart rate,respiration rate, and/or muscle spasms, the control module 202 maywirelessly transmit this information to the CIM 52 and/or one of the NIMdevices 54, 162. The NIM devices 54, 162 may then display thisinformation and/or generate an alert signal if one or more of theseparameters are outside of respective predetermined ranges and/orthresholds.

In addition to or as an alternative to monitoring the electrodes 62 todetect heart rate, respiration rate, and/or muscle spasms, the sensorincludes an accelerometer. As similarly described above, one or more ofthe control modules 202, 102, 140, 164 may monitor acceleration signalsgenerated by the accelerometer 214 to detect heart rate, respirationrate, and/or muscle spasms. This acceleration signals and/or heart rate,respiration rate, and/or muscle spasm information determined based onthe acceleration signals may be wirelessly transmitted from the sensorand/or PHY module 204 to the CIM 52 and/or one of the NIM devices 54,162.

As is further described below with respect to FIG. 21, the sensor may“self-awake”. In other words, the sensor may automatically transitionfrom being OFF or being in the low power (or sleep) mode to beingpowered ON and being in the high power mode when attached to a patient.For example, while not attached to a patient, there is an “open” circuitbetween the electrodes 62. Thus, an impedance between the electrodes 62is high (e.g., greater than 10 kilo-Ohms (kOhms)). Subsequent toattaching the sensor to the patient, an impedance between the electrodes62 is low (e.g., less than 1 kOhms) and/or significantly less then whenthe sensor was not attached. This difference in impedance can bedetected and cause the power module 206 and/or the control module 202 toswitch operating modes.

In another embodiment, the electrodes 62 and the impedance of thepatient operate as a switch to activate the power module 206. Uponactivation, the power module 206 may supply power to the control module202 and/or the PHY module 204.

In yet another embodiment, the power module 206 (or analog front end) isconfigured to generate a DC voltage while the sensor is not attached toa patient. Generation of the DC voltage may be based on the impedancebetween the electrodes 62. This DC voltage is detected by the controlmodule 202. The control module 202 remains in the low power (or sleep)mode while receiving the DC voltage. The power module 206 ceases toprovide the DC voltage when the electrodes are attached to the patient.This causes the control module to transition (i) from being OFF to beingin the low power mode or high power mode, or (ii) from being in a sleepmode to being in the low power mode or the high power mode.

The control module 202 and/or the power module 206 may periodicallytransition between operating in a low power (or sleep) mode and the highpower mode to check the impedance between the electrodes 62 and whetherthe DC voltage is provided. This may occur every predetermined period(e.g., 30-60 seconds). In another embodiment, in response to theelectrodes 62 being attached to a patient, the power module 206 maytransition (i) from not supplying power to the control module 202, thePHY module 204 and/or portions thereof to (ii) supplying power to thecontrol module 202, the PHY module 204 and/or portions thereof.

Although the modules 204, 206, 210 and the A/D converter 212 are shownas being separate from the control module 202, one or more of themodules 204, 206, 210 and the A/D converter 212 or portions thereof maybe incorporated in the control module 202. Also, the electrodes 62 mayinclude two or more electrodes. Signal lines 221 are shown for two ofthe electrodes. A third signal line 222 may be included for noisefeedback cancellation. This is described further with respect to FIGS.7A-7B.

Referring now to FIGS. 1-3 and FIG. 5, a stimulation probe device 230 isshown, which may be in communication with the CIM 52 and/or one of theNIM devices 54, 162. The stimulation probe device 230 includes a controlmodule 232, a memory 234, a PHY module 236, a stimulating module 238,electrodes 240, a power module 242, and a power source 244. Thestimulating module 238 receives power from the power module 242 andgenerates stimulation signals via the electrodes 240, which are suppliedto tissue of a patient. Although the modules 236, 238, 242 are shown asbeing separate from the control module 232, one or more of the modules236, 238, 242 or portions thereof may be incorporated in the controlmodule 232. The stimulating module 238 may detect a voltage supplied tothe electrodes 240 and/or voltage potentials applied across two of theelectrodes 240 and generate stimulation information signals indicatingthe same. The stimulating module 238 may include a current-to-voltageconversion module 246 for measuring current supplied to one or more ofthe electrodes 240 and generate a stimulation information signalindicating the same. The stimulation information signals may be providedto the control module 232.

The control module 232 wirelessly communicates with the CIM 52 and/orone or more of the NIM devices 54, 162 via the PHY module 236 and anantenna 248. The control module 232 includes a filtering module 250 anda BB module 252. The filtering module 250 may operate as a bandpassfilter and filter out frequencies of the amplified signals outside of apredetermined frequency range and a direct current (DC) voltage. Thiscan eliminate and/or minimize noise, such as 60 Hz noise. The filteringmodule 250 may receive stimulation information signals from thestimulating module 238 and convert the stimulation information signalsand/or signals generated based on the stimulation information signal toBB signals. The stimulating module 238 may monitor and indicate to thecontrol module 232 actual voltages, current levels, amplitudes, anddurations of stimulation pulses via the stimulation information signals.The control module 232 may then transmit this information via the PHYmodule 236 to the CIM 52 and/or one of the NIM device 54, 162.

The BB module 252 may include an analog-to-digital (A/D) convertingmodule 254 and convert the BB signals from the filtering module 250 todigital BB signals. The BB module 252 and/or the A/D converting module254 may sample the output of the filtering module 250 at a predeterminedrate to generate frames, which are included in the digital BB signal. ByA/D converting signals at the sensor as opposed to performing an A/Dconversion at the CIM 52 or one of the NIM devices 54, 162,opportunities for signal interference is reduced.

The BB module 252 may then upconvert the digital BB signal to anintermediate frequency (IF) signal. The BB module 252 may perform DSSSmodulation during upconversion from the digital BB signal to the IFsignal. The BB module 252 may include a mixer and oscillator forupconversion purposes. The BB module 252 and/or the control module 232may compress and/or encrypt BB signals transmitted to the PHY module 236prior to upconverting to IF signals and/or may decompress and/or decryptsignals received from the PHY module 236.

The BB module 252 may provide a received signal strength indication(RSSI) indicating a measured amount of power present in a received RFsignal. This may be used when determining which of multiple CIMs and/orNIM devices to communicate with. The control module 232 may select a CIMand/or a NIM device corresponding to a SYNC request signal and/or apayload request signal having the most power and/or signal strength.This may include selecting a channel on which the SYNC request signaland/or the payload request signal was transmitted and communicating withthe CIM or the NIM device on that channel. This allows the controlmodule 232 to select the closest and proper CIM and/or NIM device. Thisselection may be performed when the stimulation probe device has notpreviously communicated with a CIM and/or a NIM device and/or has beenreset such that the stimulation probe device does not have a record ofcommunicating with a CIM and/or a NIM device.

The memory 234 is accessed by the control module 232 and stores, forexample, parameters 260. The parameters 260 may include parametersprovided in SYNC request signals and/or parameters associated withstimulation pulses generated via the electrodes 240. The parametersassociated with stimulation pulses may include voltages, wavelengths,current levels, amplitudes, peak magnitudes, pulse durations, etc.

The PHY module 236 includes a transmit path 262 (or transmitter) and areceiver path 264 (or receiver). The transmit path 262 includes amodulation module 266 and an amplification module 268. The modulationmodule 266 modulates the IF signal to upconvert the IF signal to a RFsignal. This may include GFSK modulation. The modulation module 266 mayinclude, for example, a filter, a mixer, and an oscillator. Theamplification module 268 may include a power amplifier 269, whichamplifies the RF signal and transmits the RF signal via the antenna 248.

The receiver path 262 includes a second amplification module 270 and ademodulation module 272. The second amplification module 270 may includea LNA 274. The second amplification module 270 amplifies RF signalsreceived from the CIM. The demodulation module 272 demodulates theamplified RF signals to generate IF signals. The IF signals are providedto the BB module 252, which then downconverts the IF signals to BBsignals. The A/D converting module 254 may include a D/A converter toconvert the BB signals to analog signals. The RF signals received fromthe CIM 52 may include, for example, SYNC request signals or portionsthereof, as further described below. Examples of information included inthe SYNC request signals is shown and described below with respect toTables 1-4.

The power module 242 receives power from the power source 244 andsupplies the power to the stimulating module 238, the control module 232and the PHY module 236. The power module 242 may include a switch 276.The switch 276 may be actuated to generate stimulation pulses. When theswitch 276 is closed or toggled and/or when the control module 232generates a control signal commanding generation of one or morestimulation pulses, the power module 242 and/or the control module 232signals the stimulating module 238 to generate the one or morestimulation pulses. The timing, amplitude, and/or duration of each ofthe stimulation pulses may be based on information received from the CIM52 and/or one of the NIM devices 54, 162. Frequency of the stimulationpulses and/or time between the stimulation pulses may also be controlledand based on corresponding information received from the CIM 52 and/orone of the NIM devices 54, 162.

Referring also to FIG. 6, which shows a portion 279 of the stimulationprobe device 230. The stimulation probe device 230 includes the controlmodule 232, the stimulating module 238, the electrodes 240, the powermodule 242 with the switch 276, and the power source 244. The controlmodule 232 may be connected to the reference patch 40. In oneembodiment, the stimulating module 238 is connected to the referencepatch 40. The stimulating module 238 may include the current-to-voltageconversion module 246, a boost module 280, and a D/A converter 282. Thecurrent-to-voltage conversion module 246 converts a current supplied tothe electrodes 240 to a voltage, which is detected by the control module232. The control module 232 may include an A/D converter to convert avoltage signal received from the current-to-voltage conversion module246 to a digital signal.

The D/A converter 282 may convert an analog control signal from thecontrol module 232 to a digital control signal. The digital controlsignal is provided to the boost module 280 and sets a current level, avoltage, and a duration of one or more stimulation pulses to begenerated by the boost module 280 via the electrodes 240. The boostmodule 280 generates stimulation signals having the stimulation pulsesto be supplied to the electrodes 240. The stimulation signals haveincrease voltage, current and/or power over other signals (e.g., signalstransmitted between other modules and/or RF signals) transmitted in theWNIM system 10. The increased voltage, current and/or power generatesthe stimulation pulses to stimulate tissue (nerve or muscle tissue) of apatient. The boost module 280 receives power from the power module 242.The control module 232 may control the power module 242 to supply aselected amount of current to the boost module 280 for generation of thestimulation signals.

Although not shown, the reference patch 40 may be replaced with and/orconfigured as a “smart” reference patch that is configured to wirelesslycommunicate with the stimulation probe device 230. The smart referencepatch may, for example, be configured similar to the sensing module 50of FIGS. 2-3 and may include one or more electrodes, a control moduleand a PHY module having a transmitter path. The control module and thetransmitter path of the reference patch 40 may be configured similar toand operate similar to the control module 56 and the transmit path 74 ofthe sensing module 50 of FIG. 2 or 3. The control module of thereference patch 40 may be connected to the one or more electrodes anddetect and wirelessly transmit a reference voltage at the one or moreelectrodes to the stimulation probe device 230. The reference voltagemay be transmitted via the transmitter path of the reference patch 40.The control module of the reference patch 40 may generate a referencevoltage signal that indicates the reference voltage. The referencevoltage may be a constant voltage or may vary depending on the state ofthe patient in an area where the reference patch 40 is attached.

Referring now to FIG. 1 and FIGS. 7A-7B, which show a three-pad sensor300. The sensor 300 may replace any one of the sensors disclosed herein.The sensor 300, as shown includes a base 302 (may be referred to as apatch) having electrodes 304 and an electronic control module assembly305. The electronic control module assembly 305 that is modular andincludes a control (or sensing) module 306 mounted on a substrate 307, apower source support member 308, a power source 310, and a housing 312.In FIG. 7B, the base 302 is shown without the electronic control moduleassembly 305.

The base 302 may include a flexible substrate 314 and an adhesive layer316 attached to a bottom surface of the substrate 314. The adhesivelayer 316 may be attached to, for example, skin of a patient. Thecontrol module 306 may include a PHY module (e.g., the PHY module 204 ofFIG. 4) and a power module (e.g., the power module 206 of FIG. 4). Thecontrol module 306, the PHY module and the power module may operatesimilar to the control module 202, the PHY module 204 and the powermodule 206 of FIG. 4 and may wirelessly communicate with the CIM 52and/or one of the NIM devices 54, 162.

The power source support member 308 may be attached to the substrate 307and hold the power source 310 to the control module 306. The powersupport member 308 may be, for example, a clip. The power source 310 maybe held between the control module 306 and the power source supportmember 308. The electronic control module assembly 305 may attach to thetop of the electrodes 304 via receiving connectors 317. The receivingconnectors 317 may snap on and off of the electrodes 304. This allowsthe electronic control module assembly 305 to be modular such that theelectronic control module assembly 305 may removed from the patch andused on, for example, another patch. The electronic control moduleassembly 305 may be reusable and the patch 302 may be unreusable. Forexample, the electronic control module assembly 305 and the patch 302may be applied to one location on a patient during a first period oftime. The electronic control module assembly 305 may then be removedfrom the patch 302 and snapped onto a different patch, applied to asecond location on the patient, for use during a second period of time.As another example, the electronic control module assembly 305 and thepatch 302 may be applied to a first patient during a first period oftime. The electronic control module assembly 305 may then be removedfrom the patch 302 and snapped onto a different patch, applied to asecond patient, for use during a second period of time.

Although the sensor 300 is shown as having three electrodes 304, thesensor 300 may have two or more electrodes. The electrodes 304 extendupward from the base 302 and connect to electrically conductive pads 318on the bottom of the adhesive layer 316. The pads 318 may be in contactwith skin of a patient when attached to the patient.

The third one of the electrodes 304 may be used as a feedback terminalto supply an inverted common mode noise signal to the patient. Theinverted common node noise signal is supplied to the patient to cancelor attenuate a common node nose signal detected on the other twoelectrodes. The common node nose signal may be detected, for example, ata node between resistors of a voltage divider of the sensor. The controlmodule 306 may: monitor voltage signals at the two electrodes and thenode to detect the common node noise signal; invert the common nodenoise signal; filter the inverted common node noise signal; and feedbackthe inverted and filtered common node noise signal back to the patient.The control module 306 may feedback the inverted and filtered commonnode noise signal (referred to as a feedback signal) to cancel lowfrequency noise. This “cleans up” voltage signals detected at the twoelectrodes and used to monitor evoked tissue response signals, heartrate, respiration rate, muscle spasms, etc. The feedback signal may be,for example, a 50-60 Hz signal. As an example, the control module mayinclude four amplifiers and the voltage divider. Signals received ateach of the other two electrodes may be amplified by respective firstand second amplifiers. Outputs of the first and second amplifiers may beprovided to respective ends of the voltage divider. Voltages at the endsof the voltage divider may be provided as a differential signal toinputs of the third amplifier. An output of the third amplifier may bewirelessly transmitted to a CIM and/or NIM device. The node may beconnected between resistances of the voltage divider. A signal at thenode may be amplified via the fourth amplifier and fed back to the thirdone of the electrodes 304.

The control modules disclosed above may include digital signalprocessing algorithms that further suppress noise over that provided bythe above disclosed filters. The control modules disclosed above mayalso include algorithms for processing and distinguishing betweensignals detected via the sensors disclosed herein.

FIGS. 8-13 show an EMG endotracheal tube assembly 330 and correspondinghousing 332. FIGS. 11-13 show the housing 332 and correspondingelectronic assembly 334 of the EMG endotracheal tube assembly 330 ofFIGS. 8-10. The EMG endotracheal tube assembly 330 includes an EMG tube336 having a distal (first) end 338 and a proximal (second) end 340. Thedistal end 338 is connected to a connector 342, which may be connectedto a pump for supplying air and/or a fluid to a patient via the EMG tube336. The EMG tube 336 may be inserted in a throat of a patient and theair and/or fluid may be supplied to, for example, lungs of the patient.The proximal end 340 includes an inflatable portion 344 (shown in aninflated state), which may be used to seal off, for example, a tracheato prevent any other fluid or substance from passing around the inflatedportion 344 and entering the lungs.

The EMG endotracheal tube assembly 330 also includes the housing 332having the electronic assembly 334, electrodes 346, spring loaded pinelements 347, a first set of contacts 348, and a second set of contacts350. The electronic assembly 334, electrodes 346, spring loaded pinelements 347, and contacts 348, 350 may collectively be referred to as asensor. The electrodes 346, the contacts 348, and/or the contacts 350may be painted on the EMG tube 336. In another embodiment, theelectrodes 346, the contacts 348, and/or the contacts 350 are printed onthe EMG tube and/or are implemented as a portion of a flexible printedcircuit board (PCB).

The electrodes 346 may extend from the first set of contacts 348 to thesecond set of contacts 350. The electrodes 346 extend in parallel alongthe EMG tube 336 and are separated as to not be in contact with eachother. One or more insulation layers 352 may be applied over theelectrodes 346 to prevent external electrical contact with theelectrodes 346. Each of the insulation layers 352 may cover one or moreof the electrodes 346 and may not wrap fully around the EMG tube 336.The first set of contacts 348 are electrically in contact with springloaded pin elements 347, which are connected to a substrate 354 (orprinted circuit board). Each of the electrodes 346, the first set ofcontacts 348, and the second set of contacts 350 may include conductiveink. The insulation layers 352 may be nonconductive stamps formed ofnonconductive material (e.g., rubber).

The sensor may also include the housing 332, the substrate 354, acontrol module 355, a power source 356, power source support brackets358, an antenna 360, the spring loaded pin elements 347, and a sealinggasket 362. The housing 332 may include a first upper portion 364, asecond lower portion 366, and flanges 368. The housing 332 is formed ofa nonconductive material (e.g., plastic). The housing 332 may be shapedto encase the substrate 354, the power source 356, and the controlmodule 355 while minimizing size of the housing 332. The housing 332,via the flanges 368, snaps over the EMG tube 336. The flanges 368 opposeeach other and clasp onto the EMG tube 336. The EMG tube 336 may includeguide marks 370 for placement and attachment of the housing 332 on theEMG tube 336. The guide marks 370 may be painted on the EMG tube 336 andmay be visible underneath the housing 332 and on a side of the EMG tube336 opposite the housing 332. The EMG tube 336 is pressed between theflanges 368 and against the spring loaded pin elements 347 and thesealing gasket 362. The first portion 364 and the second portion 366 maybe sealed to each other via an adhesive, such as an ultraviolet (UV)light cured adhesive. The first portion 364 may be ultrasonically weldedto the second portion 366.

The sealing gasket 362 may be adhesively attached to both the secondportion of the housing 332 and the EMG tube 336. The sealing gasket 362is disposed between the second portion 366 of the housing 332 and theEMG tube 336. The sealing gasket 362 may have adhesive layers (oradhesive) on a first side 372 facing the second portion 366 of thehousing 332 and on a second side 374 facing the EMG tube 336. Theadhesive may be an UV light cured adhesive. The sealing gasket 362 maybeultrasonically welded to the second portion 366 and/or the EMG tube 336.The sealing gasket 362 provides a fluid tight seal to preventcontaminants from coming in contact with the first set of contacts 348and/or the spring loaded pin elements 347.

The spring loaded pin elements 347 include respective spring members 376and pins 378. The spring loaded pin elements 347 are disposed in thesealing gasket 362 and between the substrate 354 and the first set ofcontacts 348. The pins 378 are spring loaded to maintain contact withthe first set of contacts 348. Each of the spring members 376 and/or thepins 378 is in direct or indirect contact with the control module 355.These connections between the spring member 376 and the control module355 may be provided by, for example, by vias and/or traces in thesubstrate 354. The sensor may include any number of the spring loadedpin elements 347 and corresponding contacts. More than one spring loadedpin element may be provided for each of the first set of contacts 348.

The power source 356 is disposed on the substrate 354 and is held by thepower source support brackets 358, which are connected to the substrate354. The antenna 360 may be a trace printed and/or disposed on thesubstrate 354 and is connected to the control module 355. The controlmodule 355 may be configured similarly as and operate similar to any oneof the control modules of the sensors disclosed herein. The controlmodule 355, as shown has two channels. Each of the channels is connectedto a respective pair of the first set of contacts 348. The dual channelsmay be provided for redundancy reasons to assure that signals providedat the second set of contacts 350 are detected by the control module355. The second channel may be used to backup the first channel. Asdisclosed below, each of these channels may be assigned a respective oneor more time slots in communicating with a CIM and/or a NIM device.

FIG. 14 shows a plot of a stimulation pulse 390 and a correspondingevoked response signal 392. The stimulation pulse 390 may be generatedby, for example, one of the stimulation probe devices (e.g., thestimulation probe device 230 of FIG. 5) disclosed herein. The evokedresponse signal 392 may represent nerve and/or muscle activity detectedby one of the sensors disclosed herein.

Stimulation is a feature provided for nerve and/or muscle monitoring.The reaction time between stimulation and muscle response is used forboth nerve location sensing and nerve health monitoring. This can beachieved by measuring time between stimulation and reaction (e.g., timebetween a stimulation pulse and an evoked response). The wireless RFprotocol disclosed herein may include determining amounts of timebetween stimulation and evoked responses. The time between stimulationand evoked responses may be determined by the NIM devices disclosedherein.

Referring now to FIGS. 1-13, the CIMs (e.g., the CIM 52), NIM devices(e.g., the NIM devise 54, 162), sensors (e.g., the sensors 12, 13 and/orthe sensors of the embodiments of FIGS. 7A-13), stimulation probedevices (e.g., the stimulation probe devices 14, 230), and referencepatches (e.g., the smart reference patch described above) disclosedherein communicate with each other via a wireless protocol disclosedherein. The wireless protocol is designed for wireless transfer ofhigh-rate data from multiple sensors (may be referred to as remote bodysensors), stimulation probe devices and/or reference patches to the CIMsand/or the NIM devices. The sensors, stimulation probe devices andreference patches digitize signals and send the signals over-the-air(OTA) when requested by the CIMs and/or the NIM devices. Digitized datais received by the CIMs and/or NIM devices and may be converted toanalog data and/or displayed at the NIM devices.

The wireless protocol is designed for handling large amounts of datareceived at one or more high-data rates (e.g., 2.5 kHz, 5 kHz, or 10kHz). The sensors, stimulation probe devices and reference patches maybe transmitting at a same speed or may be transmitting at differentspeeds. The sensors, stimulation probe devices and reference patches mayeach transmit data on one or more channels. Each of the channels mayhave a same corresponding data rate or may have different correspondingdata rates. To transmit and handle multiple channels from multipledevices at the same or different transmission speeds, the wirelessprotocol includes sensor and stim probe synchronization protocols andlow power consumption protocols, some of which have been described abovewhiles others are described below. The wireless protocol allows fordifferent types of sensors (having different transmit speeds, number ofchannels, etc.) and different types of stimulation probe devices (havingdifferent transmit speeds, number of channels, etc.) to be connected upto the CIMs and the NIM devices. This allows for modular upgrades (e.g.,replacement of sensors and/or stimulation probe devices with increasetransmission speeds and/or number of channels).

The wireless protocol starts with a payload request, which is generatedby a NIM device. The payload request is transferred to a CIM and/or isconverted to a SYNC request. The SYNC request is a payload request andis provided as a SYNC signal. The CIM or NIM device may search for aclear channel (channel hop) and select a channel that is not used andhas a minimum amount of noise. The selected channel may then be used asa broadcast channel to transmit the SYNC request to sensors andstimulation probe devices in the corresponding WNIM system. The CIM mayupdate the SYNC request and periodically transmit the updated SYNCrequest. As an example, the CIM may wait a predetermined amount of time(referred to as a predetermined interval) between each transmission ofthe SYNC signal. The predetermined interval may be, for example, 4milli-seconds (ms).

As a result, SYNC signals may be transmitted every predeterminedinterval or 4 ms on a selected RF channel. The RF channel may be withina predetermined frequency range (e.g., 2.4-2.484 GHz). Any of thesensors and/or stimulation probe devices within range and that are‘listening’ on the broadcast channel is able to receive and interpretthe SYNC requests. The payload request and SYNC request may include apredetermined number of words (e.g. 16), where each of the words has16-bits of information. Examples of content included in the SYNC requestand the corresponding words are shown in the below provided tables 1-4.

In the following sections and else where, NIM devices, CIMs, sensors,and stimulation probe devices are described as communicating with eachother and transmitting various signals and requests between each other.Each of these transmissions may be generated and/or transmitted byrespective control modules and PHY modules of these devices, asdescribed above.

Table 1 shows an example of a payload of a SYNC request. The SYNCrequest includes 16 words, identified as words 0-15. Word 0 is a CIM orNIM device status word, the content of which is shown in table 2. Words1 and 11-12 are unused. Word 2 is a stimulation probe device statusword, the content of which is shown in Table 4. Words 3-10 are slotstatus words. An example of the content of each of the slot status wordsis shown in Table 3. Words 13-15 are stimulation information words. Word13 indicates a delay period that indicates a period between when a NIMdevice generates a payload request and a time when the NIM device or aCIM transmits a next SYNC request. A stimulation probe device may adjusttiming of data (or a data payload) transmitted from the stimulationprobe device based on the delay period. Word 14 indicates a stimulationpulse amplitude. Word 15 indicates a stimulation pulse width (orduration). A stimulation probe device may generate a stimulation pulsebased on the words 13-15. Although a certain number of each of thestimulation probe device status word, slot status words, and stimulationinformation words are shown, the payload of the SYNC request may includeany number of each of these words. For example, if more than onestimulation probe device is used, additional stimulation probe devicestatus words and/or stimulation information words may be included.Similarly, if more than 8 channels and/or more than 8 sensors arecommunicating with the CIM and/or NIM device, then additional slotstatus words may be included.

TABLE 1 SYNC Request Signal Word SYNC Request 0 Console Interface Moduleor NIM Device Status 1 Spare 2 Stimulation Probe Device Status 3 Slot 1Status 4 Slot 2 Status 5 Slot 3 Status 6 Slot 4 Status 7 Slot 5 Status 8Slot 6 Status 9 Slot 7 Status 10 Slot 8 Status 11 Spare 12 Spare 13 STIMDelay 14 STIM Amplitude 15 STIM Duration and/or Pulse Width

The CIM or NIM device status word shown in Table 2 includes 16 globalbits identified as bits 0-15. As these are global bits, all of thesensors and/or stimulation probe devices communicating with the CIMand/or NIM device may communicate according to these bits unlessotherwise indicated in a corresponding one or more of the slot statuswords or the stimulation probe device status word. Bits 0-7 (7:0)provide a CIM unique identifier (or NIM device unique identifier). Theunique identifier may be used by sensors and/or stimulation probedevices to identify a CIM and/or a NIM device when selecting a channelof a CIM and/or a NIM device. This may assure that a sensor and/or astimulation probe device communicate with the same CIM and/or NIM devicethat the sensor and/or stimulation probe device previously communicatedwith.

Bits 9:8 of the CIM or NIM device status word are request sequencer bitsused to indicate which interval sensors and/or stimulation devices areto communicate in. For example, sensors and stimulation probe devicesmay communicate in respective slots of each interval or may communicatein slots of different intervals. The sensors and/or the stimulationprobe device may communicate in one or more of a series of intervalsbased on these bits. This is further described below with respect toFIGS. 15-17.

Bits 11:10 of the CIM or NIM device status word indicate a speed (i.e.data rate) at which the sensors and/or the stimulation probe devices areto transmit information and/or data to the CIM and/or the NIM device. Inthe example shown, the data rate may be 0, 2.5 kHz, 5 kHz, 10 kHzdepending on the values of the bits 11:10. The data rate may be set lessthan or equal to a maximum data rate of one or more of the sensorsand/or stimulation probe device. In one embodiment, the data rate ofbits 11:10 of the CIM or NIM device status word may be set to the lowestmaximum data rate of the sensors to accommodate all of the sensorsand/or stimulation probe devices.

In another embodiment, the data rate of the bits 11:10 of the CIM or NIMdevice status word are set to a highest maximum data rate of thesensors. Data rates provided in the slot status words and stimulationprobe device status word are used to accommodate sensors and/orstimulation probe devices that are unable to communicate at the highestmaximum data rate. The data rate of bits 11:10 of the CIM or NIM devicestatus word may be reduced when a stimulation probe device is OFF, in asleep mode, and/or is in a low power mode. This reduces powerconsumption of the sensors and/or stimulation probe devices when data isnot being collected and/or monitored as a result of stimulation pulses.

Bits 14:12 are unused. Bit 15 indicates whether the stimulation probedevice should be ON to generate a stimulation probe signal. If bit 15 isOFF (or low), then the stimulation probe device may be OFF or in thecorresponding low power mode. The sensors and/or the stimulation probedevices may transition between OFF, sleep, low power and/or high powermodes based on bits 15 and 11:10. For example, sensors may be in a highpower mode when bits 11:10 indicate a first data rate and may be in alow power mode when the bits 11:10 indicate a second data rate, wherethe second data rate is less than the first data rate.

TABLE 2 Console Interface Module or NIM Device Status Word Bit 15 STIMON/OFF Bits 14:12 Spare Bits 11:10 Frequency (e.g., Bits 00 - 10 kHz,Bits 01 - 5 kHz, Bits 10 - 2.5 kHz, Bits 00 - 0 kHz) Bits 9:8 RequestSequencer Bits Indicating which of up to Predetermined Number of SYNCintervals (e.g., up to 4 SYNC intervals) Bits 7:0 Console UniqueIdentifier (CUID)

The slot status word shown in Table 3 includes 16 bits identified asbits 0-15. These bits may be referred to as local bits as these bitspertain to a sensor assigned to this slot. Bits 7:0 indicate whether thecorresponding time slot (referred to as “the slot”) is paired orunpaired. If paired, the slot is assigned to a sensor and bits 7:0indicate a unique identifier (SUID) of the sensor. If unpaired, the slotis not assigned to a sensor and bits 7:0 indicate a pipe address that asensor is to communicate to when communicating with the CIM or NIMdevice. Bits 9:8 indicate whether the corresponding slot is available,in process of being assigned, or is assigned. Sensors may review thesebits when determining whether to select this slot. Bits 11:10 indicate aspeed at which the sensor assigned to this slot is to transmitinformation and/or data to the CIM and/or the NIM device. Bits 13:12indicate a type of the sensor assigned to the slot. Bit 14 is unused.Bit 15 indicates whether a stimulation probe device corresponding to thesensor assigned to the slot is ON. The sensor assigned to the slot maytransition between OFF, sleep, low power, and/or high power modes basedon bit 15 and/or bits 11:10. As an example, the sensor may be OFF or inthe sleep mode and/or low power mode when bits 11:10 indicate a datarate of zero.

TABLE 3 Slot Status Word Bit 15 STIM ON/OFF Bit 14 Spare Bits 13:12SensorType - Indicating Number of channels, Speed per channel, and/orNumber of Time Slots per SYNC interval Bits 11:10 Frequency (e.g., Bits00 - 10 kHz, Bits 01 - 5 kHz, Bits 10 - 2.5 kHz, and Bits 00 - 0 kHz)Bits 9:8 Slot Status: Bits 00 - Available/Open, Bits 01 - Busy/SensorCurrently Joining, and Bits 10 - Assigned Bits 7:0 Paired (SUID) orUnpaired (Pipe Address of PHY Module of Console Interface Module or NIMdevice)

The slot status word shown in Table 4 includes 16 bits identified asbits 0-15. These bits may be referred to as local bits as these bitspertain to a stimulation probe device assigned to this slot. Bits 0:7indicate whether the corresponding time slot (referred to as “the slot”)is paired or unpaired. If paired, the slot is assigned to a stimulationprobe device and bits 0:7 indicate a unique identifier (STIMUID) of thestimulation probe device. If unpaired, the slot is not assigned to astimulation probe device and bits 0:7 indicate a pipe address that astimulation probe device is to communicate to when communicating withthe CIM or NIM device. Bits 9:8 indicate whether the corresponding slotis available, in process of being assigned, or is assigned. Astimulation probe device may review these bits when determining whetherto select this slot. Bits 10:11 indicate a speed at which thestimulation probe device assigned to this slot is to transmitinformation and/or data to the CIM and/or the NIM device. Bits 13:12indicate a type of the stimulation probe device assigned to the slot.Bit 14 is unused. Bit 15 indicates whether the stimulation probe deviceassigned to the slot is ON. The stimulation probe device assigned to theslot may transition between OFF, sleep, low power, and/or high powermodes based on bit 15 and/or bits 11:10. As an example, the stimulationprobe device may be OFF or in the sleep mode and/or low power mode whenbits 11:10 indicate a data rate of zero.

TABLE 4 Stimulation Probe Status Word Bit 15 STIM ON/OFF Bit 14:12 SpareBits 11:10 Frequency (e.g., Bits 00 - 10 kHz, Bits 01 - 5 kHz, Bits 10 -2.5 kHz, and Bits 00 - 0 kHz) Bits 9:8 Slot Status: Bits 00 -Available/Open, Bits 01 - Busy/Sensor Currently Joining, and Bits 10 -Used Bits 7:0 Paired (STIMUID) or Unpaired (Pipe Address of PHY Moduleof Console Interface Module and/or NIM device)

Sensors and stimulation probe devices, when joining a WNIM network, mayhop frequency (or broadcast) channels to detect SYNC requests. A WNIMnetwork may include one or more sensors, one or more stimulation probedevices, a CIM and/or a NIM device. The sensors and stimulation probedevices may select the channel with the strongest SYNC request at whichpoint the sensors and stimulation probe devices review slot status wordsand stimulation probe device status words in the SYNC request. Thesensors and the stimulation probe devices then select respectiveavailable time slots over which to communicate with a CIM and/or NIMdevice.

To select an available time slot, a sensor or stimulation probe devicetransmits a data payload during the selected time slot. An exampleperiodic SYNC interval is shown in FIG. 15. The periodic SYNC intervalincludes a time slot 396 in which a SYNC request is transmitted, eightsensor time slots 397, and a stimulation probe device time slot 398. Theperiodic SYNC interval is setup for two time slots per each of sensorsS1-S4. As such, each of the sensors S1-S4 has one or more unique (ordesignated) time slots to transmit a data payload in response to theSYNC request. The periodic SYNC interval has a predetermined length(e.g., 4 ms). The predetermined length is the time between consecutiveSYNC requests. The periodic SYNC interval may be referred to as a “RFframe”.

The periodic SYNC interval of FIG. 15 may support, for example, four 10kHz sensors and a stimulation probe device. Each of the four sensorssends data payloads during their designated time slots. Each of the datapayloads may include a corresponding SUID and a predetermined number(e.g., 15) of words of data. The data from the sensors may includeinformation disclosed above, such as voltage potentials, current levels,amplitudes, peak voltages (or magnitudes), etc. The data from thestimulation probe device may include information disclosed above, suchas amplitude and duration of stimulation pulses. The synchronized timingin respective time slots of the data payloads prevents data payloadresponse signals from being transmitted during a same period andcolliding with each other.

FIG. 16 provides another example of a periodic SYNC interval setup for asingle time slot per sensor and stimulation probe device. In thisexample, the data rates of the sensors and the stimulation probe devicefor the example of FIG. 16 may be half the speed of the sensors andstimulation probe device for the example of FIG. 15. For example, thesensors and the stimulation probe device for the example of FIG. 16 mayeach have an output data rate of 5 kHz. FIG. 17 provides yet anotherexample of periodic SYNC interval setup for eight sensors S1-S8. As anexample, each of the sensors S1-S8 may have a single respective timeslot and the output data rates of each of the sensors may be 5 kHz.

Although in FIGS. 15-17 a certain number of sensor time slots andstimulation probe time slots are shown per periodic SYNC interval,different numbers of sensor time slots and stimulation probe time slotsmay be included in a periodic SYNC interval. Also, although the sensorsand stimulation probe devices described with respect to each of FIGS.15-17 have a same output data rate (e.g., 10 kHz or 5 kHz), the sensorsand/or stimulation probe devices associated with one or more periodicSYNC intervals may have different output data rates. These differentdata rates may be indicated in the slot status words and stimulationprobe status words of SYNC requests. In addition, each sensor and/orstimulation probe device of a periodic SYNC interval may be designatedto a different number of time slots in that periodic SYNC interval thananother sensor and/or stimulation probe device.

The time slots of a periodic SYNC interval that are designated to asingle sensor or stimulation probe device may all be associated with asingle channel of the sensor or stimulation probe device. As anotherexample, one or more time slots of a periodic SYNC interval that aredesignated to a single sensor or stimulation probe device may beassociated with each channel of the sensor or stimulation probe device.In other words, each channel may correspond to respective sets of timeslots, where each set has one or more time slots. As another example, asensor and/or stimulation probe device may select and/or be designatedto the same or different time slots of consecutive SYNC intervals.

Additional details of the wireless protocol are described below withrespect to FIGS. 18 and 19. FIG. 18 shows a signal flow diagramillustrating a sensor 400 joining a WNIM network and communicating in aWNIM system with a CIM and/or a NIM device (collectively designated402). The sensor 400 may refer to any sensor disclosed herein.Similarly, the CIM and/or NIM device 402 may refer to any CIM and/or NIMdevice disclosed herein. Before a sensor responds to a SYNC request witha data payload, a joining process is performed. Joining establishes alink between the sensor and a CIM and/or NIM device and together thesensor and the CIM and/or NIM device (and/or other sensors and/orstimulation probe devices linked to the CIM and/or NIM device) provide aWNIM network. FIG. 18 shows an example sequence of events performed forthe sensor 400 to join the WNIM network and also how different modes ofoperation are obtained.

A SYNC request signal 404 is transmitted from the CIM and/or NIM device402 and includes a word for each time slot in a corresponding SYNCinterval and is periodically and/or continuously updated and transmittedto indicate the statuses of the slots. To join the WNIM network, thesensor 400 checks all the available slots and selects the time slot inwhich to transmit a data payload signal to the CIM and/or NIM device402. Prior to transmitting the data payload, the sensor 400 sends a joinrequest 406 to join the WNIM network and communicate in the selectedtime slot. The join request 406 may be transmitted in the selected timeslot and indicates a SUID of the sensor, the selected time slot, thetype of the sensor, a minimum data rate, and/or a maximum data rate ofthe sensor. In one embodiment, the sensor 400 sends the SUID in theselected time slot and the CIM and/or NIM device 402 has a record of thetype and data rates of the sensor.

Based on the join request 406, the CIM and/or NIM device 402 fills anappropriate slot status word with the SUID from the sensor 400. The CIMand/or NIM device 402 may then send an updated SYNC request 408 with theupdated slot status word indicating designation of the selected timeslot to the sensor 400. The sensor 400 receives the updated SYNC requestwith the SUID in the corresponding slot status word and responds bysending a data payload to the CIM and/or the NIM device 402 in theselected slot. If more than one slot is selected and/or designated tothe sensor 400, the sensor 400 may transmit one or more data payloads410 in the slots selected and/or designated to the sensor 400. The timeslots may be associated with one or more channels of the sensor 400. Thetransmission of the SYNC requests and the data payloads may beperiodically transmitted over a series of periodic SYNC intervals (or RFframes).

Once linked to the CIM and/or NIM device 402, the sensor 400 may now becontrolled by the CIM and/or NIM device 402 via transmission of updatedSYNC requests. The CIM and/or NIM device 402 may control, for example,output data rates and transitions between power modes of the sensor 400.As an example, the CIM and/or NIM device 402 may update the output datarate from 10 kHz to 5 kHz for the time slot of the sensor 400 bytransmitting an updated SYNC request 412. Sensors linked to the CIMand/or NIM device 402 inspect control bits (e.g., bits of the slotstatus words) in SYNC requests to determine respective operating and/orpower modes. The sensors then transition to the indicated operatingand/or power modes.

FIG. 19 shows a signal flow diagram illustrating a stimulation probedevice 420 joining a WNIM network and communicating in a WNIM system toa CIM and/or NIM device (collectively designated 422). The stimulationprobe device 420 may refer to any stimulation probe device disclosedherein. The CIM and/or NIM device 422 may refer to any CIM and/or NIMdevice disclosed herein. Generation of stimulation pulses may beinitiated at the NIM device and/or CIM 422. The NIM device may issue apayload request with bits 15 of status words indicating generation of astimulation pulse. The status words may include: a CIM and/or NIM statusword; slot status words; and stimulation probe status word. Based on thepayload request, the CIM may generate a SYNC request 424 also havingbits 15 of status words set to ON to indicate generation of astimulation pulse. Both the payload request and the SYNC request mayindicate a delay, an amplitude of the stimulation pulse, and/or aduration of the stimulation pulse via corresponding words 13-15. Inresponse to bits 15 indicating a stimulation pulse is to be generated,one or more sensors corresponding to the stimulation pulse device 420and/or being used to monitor the stimulation pulse to be generated maytransition to the HIGH power mode. Upon transitioning to the HIGH powermode, the sensors may generate and transmit data payloads atpredetermined default frequencies and/or at frequencies indicated bybits 11:10 of the status words of the SYNC request.

In response to the SYNC request 424, the stimulation probe device 420generates a stimulation pulse, which is provided to a patient. Toachieve an accurate timing and measurement of the stimulation pulse inrelationship to an evoked response, the delay period provided in theSYNC request 424 is monitored by the stimulation probe device 420. Thestimulation probe device 420 generates a response signal 426 indicatingthe amplitude and duration of the stimulation pulse as applied to thepatient.

Subsequent to the response signal 426 from the stimulation pulse device420, the NIM device and/or CIM 422 generates a payload request (or SYNCrequest) 428 with the stimulation bits 15 low (or OFF). In response tothe received payload request (or SYNC request) the stimulation probedevice 420 sends an acknowledgement (ACK) signal 430 to the CIM and/orNIM device 422. Generation of payload request (or SYNC requests) and ACKsignals may be repeated until a next stimulation pulse is to begenerated in which case the stimulation process may be repeated.

As described above, the CIMS, NIM devices, sensors, reference patches,and stimulation probe devices disclosed herein may communicate with eachother using bits within payload requests, SYNCH requests, data payloads,and response signals. The CIMS and/or NIM devices may initiatecommunication by a sending a payload request (SYNC request). The datapayload may include one 16-bit word for payload validation. The 16bit-word may include a SUID or a STIMUID. When the CIM and/or NIM devicereceives a data payload, the CIM and/or NIM device compares the SUID orthe STIMUID with an expected SUID or STIMUID stored in memory of the CIMand/or NIM device. The SUID or STIMUID may have been stored in thememory when the sensor or stimulation probe device joined thecorresponding WNIM network. If the comparison indicates a match, thedata in the data payload may be displayed at the NIM device.

Likewise, when the sensor receives the SYNC request, the sensor comparesthe CUID of the CIM and/or NIM device provided in the SYNC request withan expected CUID stored in a memory of the sensor. The CUID may havebeen stored in the memory when the sensor joined the corresponding WNIMnetwork. If the comparison of the CUIDs indicates a match, the sensormay respond, depending on mode status bits within a slot status word ofthe SYNC request, with one or more data payloads in the appropriate timeslots following the SYNC request. The mode status bits may be the bitsof the slot status word indicating a data rate and/or whether astimulation pulse is to be generated.

The systems, devices and modules disclosed herein may be operated usingnumerous methods, in addition to the methods described above, someadditional example methods are illustrated in FIGS. 20-22. In FIG. 20, amethod of operating a sensor and a CIM and/or NIM device is shown.Although the following tasks are primarily described with respect to theimplementations of FIGS. 1-4 and 7A-13, the tasks may be easily modifiedto apply to other implementations of the present disclosure. The tasksmay be iteratively performed.

The method may begin at 500. At 502, electromyographic signals aregenerated due to, for example, generation of a stimulation pulse. Theelectromyographic signals are detected by a control module (e.g., one ofthe control modules 56, 202) via electrodes. At 504, a gain module(e.g., the gain module 63) adjusts gain of the electromyographicsignals. At 506, a filtering module (e.g., the filtering module 64)filters an output of the gain module. The filtering module may bandpassfilter amplified electromyographic signals received from the gainmodule.

At 508, a BB module (e.g., the BB module 66) generates a BB signal basedon the filtered and amplified electromyographic signals. At 510, amodulation module (e.g., the modulation module 78) modulates andupconverts the BB signal to generate an RF signal. At 514, a PHY module(e.g., one of the PHY modules 60, 204) and/or an amplification module(e.g., the amplification module 80) transmits the RF signal from thesensing module to a CIM and/or NIM device.

At 516, the CIM and/or NIM device receives the RF signal from thesensing module and amplifies the RF signal. At 518, a demodulationmodule (e.g., one of the demodulation modules 114, 176) downconverts theRF signal to generate a second BB signal. At 522, a BB module (e.g., oneof the BB modules 128, 184) at the CIM and/or NIM device may attenuatethe second BB signal, as described above. At 524, a filtering module(e.g., one of the filtering modules 126, 186) filters the attenuatedsecond BB signal to generate a second filtered signal. This may includebandpass or low pass filtering.

At 526, the second filtered signal may be provided from the CIM to theNIM device. At 528, the NIM device may display the second filteredsignal. As similar method as that shown with respect to FIG. 20 may beperformed for data requested and received from a stimulation probedevice. The method may end at 530.

In FIG. 21, a method of powering-up a sensor is shown. Although thefollowing tasks are primarily described with respect to theimplementations of FIGS. 1-4 and 7A-13, the tasks may be easily modifiedto apply to other implementations of the present disclosure. The tasksof FIG. 21 may be iteratively performed. The method may begin at 550.

At 552, an electromyographic signal is generated and/or an impedancebetween electrodes decreases due to attachment of the sensor to apatient. At 554, a power module (e.g., the power module 206) determineswhether the impedance is less than a predetermined impedance (orthreshold). If the impedance is less than the predetermined impedance,task 560 may be performed as shown, or alternatively task 556 may beperformed. If the impedance is greater than or equal to thepredetermined impedance, one or more of tasks 560, 561, 562, 564 may beperformed. Although tasks 560, 561, 562, 564 are shown, any one of thetasks may not be performed and/or may be skipped. Also, tasks 560, 561,562, 564 may be performed in a different order.

At 560, a control module (e.g., one of the control modules 56, 202)determines whether a DC voltage (may be referred to as an output voltageor output voltage signal) has been received from a power module (e.g.,the power module 206), as described above. If a DC voltage is notreceived task 556 may be performed. If a DC voltage is received, task561 is performed.

At 556, a sensing module of the sensor transitions to a LOW power modeor a HIGH power mode, which may include powering ON a portion, all, or aremaining portion of the control module and/or the PHY module. As anexample, if a stimulation pulse is to be generated, the power module maytransition to the HIGH power mode and power ON all or a remainingportion of the control module and/or the PHY module that are not alreadypowered ON. Subsequent to task 556, the method may end at 558.Subsequent to task 556, the control module may proceed to, for example,task 504 of FIG. 20.

At 561, the power module may determine whether a voltage potentialacross the electrodes is greater than a predetermined voltage and/or hasa magnitude that is greater than a predetermined magnitude. If thevoltage potential is greater than the predetermined voltage and/or themagnitude is greater than the predetermined magnitude, task 556 may beperformed, otherwise task 562 may be performed. In one embodiment, astimulation probe device is used to activate sensors. The stimulationprobe device generates an initial stimulation pulse to active thesensors. Additional stimulation pulses may be generated after thesensors are activated. The power module may detect the initialstimulation pulse by monitoring the voltage at the electrodes and/oramplified signals generated based on the voltage detected at theelectrodes.

At 562, the power module may determine whether an amount of currentreceived from one of the electrodes is greater than a predeterminedcurrent level. If the amount of current is greater than thepredetermined current level, task 556 may be performed, otherwise task564 may be performed. As stated above, a stimulation probe device maygenerate an initial stimulation pulse to activate sensors. The powermodule may detect the initial stimulation pulse by monitoring currentreceived from one or more of the electrodes and/or amplified signalsgenerated based on the current received from the one or more electrodes.In one embodiment, tasks 561 and/or 562 are performed and tasks 554and/or 560 are not performed.

At 564, the power module refrains from generating the output voltage (oroutput signal) and the sensing module refrains from transitioning to thelow power mode or the high power mode and remains in the sleep modeand/or low power mode. Subsequent to task 564, task 552 may be performedas shown or the method may end at 558.

In FIG. 22, a WNIM method of operating a stimulation probe device, oneor more sensors, and a console interface module and/or NIM device isshown. Although the following tasks are primarily described with respectto the implementations of FIGS. 1-19, the tasks may be easily modifiedto apply to other implementations of the present disclosure. The tasksof FIG. 21 may be iteratively performed. The following tasks provide anexample of initial power-ON and continuous and initial generation ofperiodic SYNC requests. The method may begin at 600.

At 602, sensors and one or more stimulation probe devices receive one ormore SYNC requests from one or more CIMs and/or NIM devices. The controlmodules of the NIM devices may generate payload request signalsrequesting data payloads from sensors and stimulation probe devices. Thecontrol modules of the CIMS may each generate a SYNC request signal,which may be transmitted periodically (e.g., once every predetermined orSYNC) period).

At 604, a stimulation probe device selects a broadcast channel of one ofthe SYNC requests based on, signal strengths of the SYNC requests asreceived by the stimulation probe device. The stimulation probe devicemay hop through channels in a table to receive the SYNC requests. Thebroadcast channel of the SYNC request with the greatest signal strengthis selected. The stimulation probe device may determine whether there ismore than one stimulation probe device in the WNIM network of theselected SYNC request. If there is more than one stimulation probedevice, an available time slot is selected by the stimulation probedevice that is joining the WNIM network. This may be accomplishedsimilar to how a sensor selects a time slot, as described above.

At 605, the stimulation probe device joining the WNIM network determinesthat a stimulation pulse is not to be generated based on correspondingstatus bits of the SYNC request of the selected broadcast channel. At606, the stimulation probed device sends an ACK signal to the CIM and/ora NIM device of the selected broadcast channel.

At 607, the stimulation probe device receives an updated SYNC requestfrom the CIM and/or NIM device of the selected broadcast channel.

At 608, the stimulation probe device that has joined the WNIM networkdetermines whether a stimulation pulse is to be generated based oncorresponding status bits of the updated SYNC request of the selectedbroadcast channel. If a stimulation pulse is requested to be generated,task 610 is performed, otherwise task 609 is performed. At 609, thestimulation pulse device sends an ACK signal to the CIM and/or NIMdevice of the selected broadcast channel.

At 610, the stimulation pulse device generates a stimulation pulsesignal based on stimulation information words in the SYNC request. Thestimulation pulse signal may be generated according to a delay period,an amplitude, and/or a duration provided in the SYNC request. At 612,the stimulation probe device reports a measured (or detected) amplitudeand duration of the generated stimulation pulse to the CIM and/or theNIM device in a designated time slot of the periodic SYNC interval. Thismay occur in the same periodic SYNC interval as the SYNC request. Task607 may be performed subsequent to task 612 or the method may end at 630as shown.

At 620, each of the sensing modules selects a broadcast channel of aSYNC request with a greatest signal strength. The sensing modules mayhop through channels in tables stored in the sensing modules to find andselect the broadcast channel. At 622, each of the sensing modules of thesensors selects one or more time slots and/or checks statuses of timeslots as indicated in the SYNC request of the selected broadcastchannel. If a sensing module has not linked up previously to the CIMand/or the NIM device communicating the selected broadcast channel, thenthe sensing module selects an available time slot. If a sensing modulehas previously linked up to the CIM and/or NIM device, then the sensingmodule checks a status of the previously selected time slot to assurethat the time slot is still designated to the sensing module. If thetime slot is no longer designated to the sensing module, the sensingmodule may select another available time slot.

Multiple time slots may be designated to a sensing module based on atype of the corresponding sensor without the sensing module havingpreviously requested multiple time slots. For example, if the sensor hasmultiple channels and/or is to be assigned multiple time slots, the CIMand/or NIM device may update slot status words accordingly based on asingle slot request. The sensing module may then detect that multipleslots have been assigned during review of slot status words in asubsequent SYNC request.

At 624, the sensing modules may send data payloads in the respectivelyselected time slots. This serves dual purposes. In addition to providingdata corresponding to signals detected at electrodes of the sensors, thesent data payloads serve as a request for the selected time slots. At626, the sensing modules may receive a next updated SYNC request fromthe CIM and/or NIM device. The next updated SYNC request may indicateSUIDs of the sensing modules in slot status words. Task 626 may beperformed while task 607 is performed. Tasks 626 and 607 may refer tothe same updated SYNC request.

At 628, the sensing modules send data payloads in the designated timeslots according to the updated SYNC request to the CIM and/or NIMdevice. Task 628 may be performed subsequent to task 610. Task 626 maybe performed subsequent to task 628 or the method may end at 630 asshown. Although not shown in FIG. 22, some of the tasks may beiteratively performed for subsequent SYNC request signals and/orgeneration of additional stimulation pulses.

The above-described tasks of FIGS. 20-22 are meant to be illustrativeexamples; the tasks may be performed sequentially, synchronously,simultaneously, continuously, during overlapping time periods or in adifferent order depending upon the application. Also, any of the tasksmay not be performed or skipped depending on the implementation and/orsequence of events.

FIGS. 23-24 show a portion 700 of another EMG endotracheal tube assemblyincluding a housing 702 and a corresponding electronic assembly 704. TheEMG tube assembly may replace or be used instead of the EMG tubeassembly of FIGS. 8-13 and may include any of the modules describedabove with respect to any of the sensors disclosed herein. The housing702 is connected to an endotracheal tube 706 via flanges 707. Thehousing 702 includes a top portion (or cover) 708 and a bottom portion709. The EMG endotracheal tube assembly includes the housing 702 havingthe electronic assembly 704, electrodes 710, spring loaded pin elements712, and contacts 714. The electronic assembly 704, electrodes 710,spring loaded pin elements 712, and contacts 714 may collectively bereferred to as a sensor. The sensor may also include the housing 702, asubstrate 716, a control (or sensing) module 718, a power source 720, anantenna 722, the spring loaded pin elements 712, and a sealing gasket724.

The EMG endotracheal tube assembly of FIGS. 23-24 provides a low profilevariant of the EMG endotracheal tube assembly of FIGS. 8-13. The powersource (or battery) 720 has a “flat” or low-profile, which allows thehousing 702 to have a lower profile than the housing 332. The powersource 720 may be a “flatpack” battery, a lithium ion polymer (LiPON)battery, a wafer-scaled battery, or other planar packaged power source.

FIGS. 25-34 show a sensor assembly 750 incorporating a modular control(or sensing) module assembly 752, and including one or more of (i) apatch 754 with electrodes 755, and (ii) a pin electrode adaptor 756 withelectrodes 758 and pin electrodes 760. The patch 754 may include a basehaving a flexible substrate and an adhesive layer with pads 762 (similarto the base 302 of FIGS. 7A-7B). The patch 754 provides electricalconnections between the electrodes 755 and the pads 762. The pinelectrode adaptor 756 provides electrical connections between theelectrodes 758 and the pin electrodes 760. The patch 754 and the pinelectrode adaptor 756 may include passive devices and may not includeactive (or smart) devices. The sensor assembly 750 or portions thereofmay be used in replacement of any of the sensors shown in FIG. 1 and mayinclude any of the modules described above with respect to any of thesensors disclosed herein.

The modular control module assembly 752 may be snapped onto theelectrodes 755 of the patch 754 or may be snapped onto the electrodes758 of the pin electrode adaptor 756. The modular control moduleassembly 752 and the pin electrode adaptor 756 may replace one of thesensors 12 of FIG. 1. The modular control module assembly 752 and thepatch 754 may replace one of the sensors 13 of FIG. 1.

FIGS. 29 and 34 illustrate receiving connectors 766 that connect to theelectrodes 755 of the patch 754 and the electrodes 758 of the pinelectrode adaptor 756. The electrodes 755, 758 may be inserted into orplug into the receiving connectors 766. The electrodes 755, 758 may haveone or more ribs (e.g., ribs 768) and recessed portions (e.g., recessedportions 770) that match corresponding portions of the receivingconnectors 766, as shown in FIGS. 25, 28 and 33. The modular controlmodule assembly 752 may be reusable and the patch 754 and the pinelectrode adaptor 756 may not be reusable, as similarly described abovewith respect to the sensor of FIGS. 7A-7B. This minimizes system costsby allowing the modular control module assembly 752 to be reusedmultiple times, as opposed to being disposed of after being used onceand/or for a single surgical procedure. In one embodiment, the modularcontrol module assembly 752: is not reusable; may be connected to orinclude the patch 754 and/or the pin electrode adaptor 756; and may notsnap onto the patch 754 or the pin electrode adaptor 756.

Referring now to FIG. 4 and FIG. 35, which shows a portion 800 (referredto as a front end circuit) of a power module (e.g., the power module 206of FIG. 4). The portion 800 includes resistances R1, R2, which areconnected to the electrodes 62. The resistance R1 is connected betweenone of the electrodes 62 and a voltage source providing voltage V+. Theresistance R2 is connected between another one of the electrodes 62 anda voltage source or reference voltage V− (e.g., ground reference).

The portion 800 further includes capacitances C1, C2, resistances R3,R4, R5, R6, capacitances C3, C4, C5, an amplifier module 801, and adetection module 802. The capacitances C1, C2 are connected in seriesrespectively with two of the electrodes 62 and are connectedrespectively between the resistances R1, R2 and the resistances R3, R4.The resistances R3, R4 are connected in series (i) between thecapacitances C1, C2, and (ii) between the resistances R5, R6. Thecapacitance C1 and each of the resistances R3, R5 are connected to eachother at terminal 803. The capacitance C2 and each of the resistancesR4, R6 are connected to each other at terminal 805.

The resistances R1, R2, R3, R4 provide a voltage divider between voltageterminals 804, 806, which receive the voltages V+, V−. The resistancesR5, R6 are connected in series respectively with the capacitances C1, C2and are connected in series with capacitance C5. The capacitance C5 isconnected between the resistances R5, R6. The capacitances C3, C4 areconnected in series with each other and between the resistances R5 andR6. The capacitance C5 is connected across the capacitances C3, C4. Aterminal 808 between resistances R3, R4 is connected to a terminal 810between capacitances C3, C4. Each of the resistances R3, R4 areconnected to each of the capacitances C3, C4 via the terminals 808, 810.The amplifier module 801 includes (i) two inputs that are connectedrespectively to ends of the capacitance C5, and (ii) an output that isconnected to the detection module 802.

The capacitance C1 and resistance R3 operate as a first high passfilter. The capacitance C2 and resistance R4 operate as a second highpass filter. The resistance R5 and the capacitance C3 operate as a firstlow pass filter. The resistance R6 and the capacitance C4 operate as asecond low pass filter.

During operation, if a patient is not connected to the electrodes 62,then an imbalance exists across the terminals 803, 805 such that avoltage at the terminal 803 is pulled up to the voltage V+ viaresistance R1 and capacitance C1 and a voltage at the terminal 805 ispulled down to the voltage V− via resistance R2 and capacitance C2. Thecapacitances C1, C2 provide DC voltage blocking, but may exhibitleakage, which may be detected and amplified by the amplifier module801. The voltage out of the amplifier module 801 is detected by thedetection module 802. The detection module may generate a DC voltagewhen the patient is not connected to the electrodes 62. The DC voltagemay then be provided to the control module 202 for detection that thepatient is not connected to the electrodes 62. This is referred to as“lead-off” detection. As an example, a voltage difference between V+ andV− is between 2-5V.

If the patient is connected to the electrodes 62, then the imbalanceacross the terminals 803, 805 decreases because the voltage potentialdifference between the terminals 803, 805 decreases. This change involtage, after filtering, is amplified by the amplifier module 802 anddetected by the control module 202. The amplifier module 801 may includean amplifier for amplifying voltages across the capacitance C5. Thedetection module may not generate and/or provide the DC voltage to thecontrol module 202 when the voltage potential difference between theterminals 803, 805 decreases.

There is a subtle effect, especially due to the DC blocking capacitancesC1, C2. The resistances R1, R2, R3, R4, the capacitances C1, C2 and thevoltage V+, V− are set to allow for lead-off detection and lead-ondetection while minimizing current that could potentially pass to thepatient via the electrodes 62. Current may follow a current path fromthe terminal 804 through the resistance R1, the capacitance C1, theresistances R3, R4, the capacitance C2 and then through the resistanceR2 to the terminal 806. If there is, for example, 5 nano-amperes (nA) ofcurrent passing along this path, then there may be 100 micro-volts (pV)across the resistances R3, R4. If the amplifier module 801 provides again of 150, the output of the amplifier module 801 may be 15milli-volts (mV) DC, which may be detected by the detection module 802.

The circuit shown in FIG. 35 may be used to alert a user that a sensoris disconnected from a patient and/or to wake up the sensor. In oneembodiment, the portion 800, the power module 206, the control module202, and/or a portion thereof periodically wakes up and checks whether apatient is attached to the electrodes 62. As an example, the powermodule 206 may periodically wake up and detect whether a patient isattached and inform the control module 202. As another example, thecontrol module 202 may periodically wake up the power module 206 toperform this detection.

As yet another example, the portion 800 may include a timing module 810,which may receive power from the power source 208. The power source 208may also provide the voltages V+, V− or the power module may generatethe voltages V+, V− based on power from the power source 208. The timingmodule 810 may periodically wake up and supply power to the resistancesR1, R2, the amplifier module 801 and/or the detection module 802. Thedetection module 802 may then detect whether a patient is attached tothe electrodes 62. If the electrodes 62 are attached to a patient, thedetection module may inform the control module 202 and/or power up thecontrol module 202 and/or the PHY module 204.

The wireless communication and corresponding systems and devicesdisclosed herein provides several advantages. For example, the wirelesscommunication and corresponding systems and devices provide improvedsignal-to-noise ratios due at least partially to elimination of largeloops of wire associated with traditional systems. The wirelesscommunication and corresponding systems and devices also electricallyisolate a patient from monitoring devices. This provides improved safetyby minimizing the amount of electrical current that may be supplied to apatient.

The wireless communications described in the present disclosure can beconducted in full or partial compliance with IEEE standard 802.11-2012,IEEE standard 802.16-2009, and/or IEEE standard 802.20-2008. In variousimplementations, IEEE 802.11-2012 may be supplemented by draft IEEEstandard 802.11ac, draft IEEE standard 802.11ad, and/or draft IEEEstandard 802.11ah.

The foregoing description is merely illustrative in nature and is in noway intended to limit the disclosure, its application, or uses. Thebroad teachings of the disclosure can be implemented in a variety offorms. Therefore, while this disclosure includes particular examples,the true scope of the disclosure should not be so limited since othermodifications will become apparent upon a study of the drawings, thespecification, and the following claims. As used herein, the phrase atleast one of A, B, and C should be construed to mean a logical (A OR BOR C), using a non-exclusive logical OR, and should not be construed tomean “at least one of A, at least one of B, and at least one of C.” Itshould be understood that one or more steps within a method may beexecuted in different order (or concurrently) without altering theprinciples of the present disclosure.

In this application, including the definitions below, the term ‘module’or the term ‘controller’ may be replaced with the term ‘circuit.’ Theterm ‘module’ may refer to, be part of, or include: an ApplicationSpecific Integrated Circuit (ASIC); a digital, analog, or mixedanalog/digital discrete circuit; a digital, analog, or mixedanalog/digital integrated circuit; a combinational logic circuit; afield programmable gate array (FPGA); a processor circuit (shared,dedicated, or group) that executes code; a memory circuit (shared,dedicated, or group) that stores code executed by the processor circuit;other suitable hardware components that provide the describedfunctionality; or a combination of some or all of the above, such as ina system-on-chip.

The module may include one or more interface circuits. In some examples,the interface circuits may include wired or wireless interfaces that areconnected to a local area network (LAN), the Internet, a wide areanetwork (WAN), or combinations thereof. The functionality of any givenmodule of the present disclosure may be distributed among multiplemodules that are connected via interface circuits. For example, multiplemodules may allow load balancing. In a further example, a server (alsoknown as remote, or cloud) module may accomplish some functionality onbehalf of a client module.

The term code, as used above, may include software, firmware, and/ormicrocode, and may refer to programs, routines, functions, classes, datastructures, and/or objects. The term shared processor circuitencompasses a single processor circuit that executes some or all codefrom multiple modules. The term group processor circuit encompasses aprocessor circuit that, in combination with additional processorcircuits, executes some or all code from one or more modules. Referencesto multiple processor circuits encompass multiple processor circuits ondiscrete dies, multiple processor circuits on a single die, multiplecores of a single processor circuit, multiple threads of a singleprocessor circuit, or a combination of the above. The term shared memorycircuit encompasses a single memory circuit that stores some or all codefrom multiple modules. The term group memory circuit encompasses amemory circuit that, in combination with additional memories, storessome or all code from one or more modules.

The term memory circuit is a subset of the term computer-readablemedium. The term computer-readable medium, as used herein, does notencompass transitory electrical or electromagnetic signals propagatingthrough a medium (such as on a carrier wave); the term computer-readablemedium may therefore be considered tangible and non-transitory.Non-limiting examples of a non-transitory, tangible computer-readablemedium include nonvolatile memory circuits (such as a flash memorycircuit or a mask read-only memory circuit), volatile memory circuits(such as a static random access memory circuit and a dynamic randomaccess memory circuit), and secondary storage, such as magnetic storage(such as magnetic tape or hard disk drive) and optical storage.

The apparatuses and methods described in this application may bepartially or fully implemented by a special purpose computer created byconfiguring a general purpose computer to execute one or more particularfunctions embodied in computer programs. The computer programs includeprocessor-executable instructions that are stored on at least onenon-transitory, tangible computer-readable medium. The computer programsmay also include or rely on stored data. The computer programs mayinclude a basic input/output system (BIOS) that interacts with hardwareof the special purpose computer, device drivers that interact withparticular devices of the special purpose computer, one or moreoperating systems, user applications, background services andapplications, etc.

The computer programs may include: (i) assembly code; (ii) object codegenerated from source code by a compiler; (iii) source code forexecution by an interpreter; (iv) source code for compilation andexecution by a just-in-time compiler, (v) descriptive text for parsing,such as HTML (hypertext markup language) or XML (extensible markuplanguage), etc. As examples only, source code may be written in C, C++,C#, Objective-C, Haskell, Go, SQL, Lisp, Java®, ASP, Perl, Javascript®,HTML5, Ada, ASP (active server pages), Perl, Scala, Erlang, Ruby,Flash®, Visual Basic®, Lua, or Python®.

None of the elements recited in the claims is intended to be ameans-plus-function element within the meaning of 35 U.S.C. § 112(f)unless an element is expressly recited using the phrase “means for”, orin the case of a method claim using the phrases “operation for” or “stepfor”.

1. A method comprising: receiving a payload request from a console interface module or a nerve integrity monitoring device; receiving, at a sensing module, a first electromyographic signal from a patient via a plurality of electrodes, wherein the sensing module is directly connected to the plurality of electrodes; generate a first voltage signal based on the electromyographic signal; upconverting the first voltage signal to a first radio frequency signal; and based on the payload request, wirelessly transmitting the first radio frequency signal from the sensing module to the console interface module or the nerve integrity monitoring device.
 2. The method of claim 1, further comprising transmitting a data payload to the console interface module or the nerve integrity monitoring device at a data rate, wherein: the payload request includes the data rate; and the data payload includes data generated based on the first electromyographic signal.
 3. The method of claim 1, further comprising: determining status of a plurality of time slots based on a plurality of slot status words, and (ii) selecting one or more of the time slots, wherein the payload request includes the plurality of slot status words; and transmitting one or more data payloads in the selected one or more of the time slots.
 4. The method of claim 3, further comprising: periodically receiving synchronization request signals from the console interface module or the nerve integrity monitoring device, wherein synchronization intervals exist between transmission of consecutive pairs of the synchronization request signals; and transmitting a plurality of data payloads in the selected one or more of the time slots of the synchronization request signals.
 5. The method of claim 1, further comprising: detecting an impedance between the plurality of electrodes; and based on the impedance, powering up a portion of a control module of the sensing module or a portion of a physical layer module of the sensing module.
 6. The method of claim 1, further comprising: detecting an impedance between the plurality of electrodes; and based on the impedance, powering up a control module and a physical layer module, wherein the sensing module comprises the control module and the physical layer module.
 7. The method of claim 6, further comprising, based on the impedance, enabling supply of power from a power source to the control module or the physical layer module, wherein the sensing module comprises the control module and the physical layer module.
 8. The method of claim 7, comprising powering up the control module or the physical layer module if the impedance is less than a predetermined impedance.
 9. The method of claim 1, further comprising: detecting a voltage across the plurality of electrodes; and based on the voltage powering up a portion of a control module or a portion of a physical layer module, wherein the sensing module comprises the control module and the physical layer module.
 10. The method of claim 1, further comprising: detecting an amount of current received at one of the plurality of electrodes; and based on the amount of current powering up a portion of a control module or a portion of a physical layer module, wherein the sensing module comprises the control module and the physical layer module.
 11. The method of claim 1, further comprising: supplying a voltage to a control module of the sensing module via a power module; and based on whether the control module is receiving the voltage, transitioning the power module from (i) being OFF to being in a low power mode or a high power mode, or (ii) being in the low power mode to being in the high power mode.
 12. The method of claim 1, wherein the electrodes are on an endotracheal tube.
 13. The method of claim 1, further comprising: detecting a temperature and generating a temperature signal; and wirelessly transmitting the temperature signal to the console interface module or the nerve integrity monitoring device.
 14. The method of claim 1, further comprising: generating an acceleration signal via an accelerometer; and wirelessly transmitting the acceleration signal to the console interface module or the nerve integrity monitoring device.
 15. A method, comprising: receiving a request from a console interface module or a nerve integrity monitoring device; receiving from a plurality of electrodes in a housing of a sensing module a first electromyographic signal from a patient; generating a first voltage signal based on the electromyographic signal; wirelessly transmitting a first radio frequency signal from the sensing module based upon the first voltage signal to the console interface module or the nerve integrity monitoring device; and detecting at least one of an impedance, a voltage, or a current at the plurality of electrodes and powering up at least a portion of a control module or a portion of a physical layer module in the sensing module based upon the detection of the at least one of the impedance, voltage, or current.
 16. The method of claim 15, wherein receiving the first electromyographic signal from the plurality of electrodes includes receiving the first electromyographic signal from the plurality of electrodes on an endotracheal tube.
 17. The method of claim 15, further comprising: detecting a temperature and generating a temperature signal; and wirelessly transmitting the temperature signal to the console interface module or the nerve integrity monitoring device.
 18. The method of claim 15, further comprising: generating an acceleration signal via an accelerometer; and wirelessly transmitting the acceleration signal to the console interface module or the nerve integrity monitoring device.
 19. A method, comprising: receiving a payload request from a console interface module or a nerve integrity monitoring device, wherein the payload request includes a data rate; receiving, at a plurality of electrodes of a sensing module, a first electromyographic signal from a patient; generating a first voltage signal based on the electromyographic signal; upconverting the first voltage signal to a first radio frequency signal; and wirelessly transmitting based on the payload request, the first radio frequency signal having a data payload at the data rate from the sensing module to the console interface module or the nerve integrity monitoring device.
 20. The method of claim 19, further comprising: determining status of a plurality of time slots based on a plurality of slot status words, and (ii) selecting one or more of the time slots, wherein the payload request includes the plurality of slot status words; and transmitting one or more data payloads in the selected one or more of the time slots. 